Momentum

1. 1

   +9.6 points. On June 8, 2017, Jeremy Corbyn's Labour reached 40% and gained 30 seats; the Conservatives stayed first but lost their majority.

2. 2

   About 24,000 members, few staff. Momentum trained more than 3,000 volunteers in persuasion conversations.

3. 3

   100,000 people. That's how many Momentum sent to marginal seats, using a search website and lift-sharing.

4. 4

   About 10,000 on the doorstep on polling day, by Momentum's own account, plus cheap satirical videos and WhatsApp reminders.

5. 5

   Where a few seats decide, train the base and take it to the seats where each door counts most.

Copy summary

If you're new to this, start with the fundamentals, from the vote goal to what the research says. Read the fundamentals

This playbook is built from what Momentum itself published about the campaign, interviews its organisers and trainers gave between 2017 and 2019, and academic studies of so-called satellite campaigns. Most of the reach figures come from the organisation itself.

• Adam Klug

  Co-founder and national coordinator of Momentum

  Introduced distributed volunteer organising techniques in Corbyn's 2016 leadership campaign and played a leading role in designing and running the 2017 campaign.

  Sources

• Emma Rees

  Co-founder and national coordinator of Momentum

  One of the three staff members who built the organisation; she later explained in interviews what 2017 taught about using volunteers' energy.

  Sources

• Erika Uyterhoeven and Jeremy Parkin

  Former Bernie Sanders campaign organisers, volunteer trainers

  With two other former Sanders staffers, they planned the persuasion canvassing training unpaid, from Momentum's London office.

  Sources

• Beth Foster-Ogg

  Momentum's national training organiser

  Coordinated the workshops that continued after the election and brought participants into a Slack group for the next sessions.

  Sources

• Jamie Driscoll

  Momentum training coordinator (2017)

  Led training on talking with Conservative voters, with role-play exercises and the rule of explaining each policy in ten seconds.

  Sources

• Laura Parker

  Momentum national coordinator (2017–2019)

  Led the scale-up of the operation for the 2019 election and described Momentum as a bridge between the movement and the party.

  Sources

• Adam Peggs

  Momentum activist and Red Pepper writer

  Released the final-week video audience figures and wrote the assessment of what still had to be built after June 2017.

  Sources

What organisers and trainers said about the decisions they made. Paraphrased unless in quotation marks.

• The heart of the training was “acknowledging concerns and building empathy” with whoever opened the door.

  Jeremy Parkin, former Sanders organiser and volunteer trainer, New Statesman, “Almost every constituency we targeted, we won”, 14 Jun 2017

• “Almost every constituency Momentum targeted, we won.”

  Jeremy Parkin, former Sanders organiser, New Statesman, 14 Jun 2017

• Early in 2017, a three-person staff could not keep up with every volunteer enquiry and many emails went unanswered: a staff-heavy model cannot harness all the energy available.

  Emma Rees, co-founder, Tribune, Momentum’s Election Gameplan, 16 Nov 2019

• Sharing the strategy openly helps volunteers understand the plan and commit to it; that is worth more than any advantage of secrecy.

  Emma Rees, co-founder, Tribune, 16 Nov 2019

When Theresa May called the election, almost nobody gave Labour a chance. Momentum had been founded in 2015 to back Corbyn and had about 24,000 members, a handful of staff and £2,000 for Facebook. In seven weeks it turned a base concentrated in safe seats into a mobile force in the seats that decided the election.

40%

of the vote for Labour (12.9 million), up 9.6 points with 30 more seatsofficial

100,000

people used My Nearest Marginal to find a marginal seat and a liftcampaign figure

1.2M

doors knocked on polling day by about 10,000 volunteers who took the day offcampaign figure

3,000

volunteers trained in persuasion conversations, in more than 40 sessionscampaign figure

From founding to a hung parliament

1. 8 Oct 2015Jon Lansman, Adam Klug, Emma Rees and James Schneider found Momentum, four weeks after Corbyn wins the Labour leadership.
2. 2016In Corbyn's leadership campaign, Adam Klug heads national volunteer mobilisation and tests distributed organising techniques.
3. Feb 2017Momentum carpools take activists from across the country to the Copeland and Stoke Central by-elections: the seed of the model.
4. 18–19 Apr 2017May announces an election for 8 June; Parliament approves it 522 to 13. The Conservatives lead by 21 points. Momentum starts planning immediately.
5. Apr–JunFormer Sanders organisers build the training: more than 40 sessions, three or four a week, 20 to 300 people each. My Nearest Marginal goes live.
6. May–JunMomentum's satirical videos, such as the one where a girl in 2030 asks her Tory father whether he hates her, rack up millions of views.
7. Final weekAccording to Momentum, the videos get more than 23 million views from 12.7 million different people. The Birmingham rally passes 2 million on Facebook.
8. 8 Jun 2017According to Momentum, about 10,000 volunteers take the day off and knock on more than 1.2 million doors; the WhatsApp cascade reaches 400,000 people. Labour at 40%, 262 seats; hung parliament.
9. 12 Dec 2019With a scaled-up operation (more staff, Labour Legends, My Campaign Map), Labour falls to 32.1% and 202 seats, its worst result since 1935.
10. 2020–2026Starmer takes over Labour; Corbyn is suspended from the party in 2020 and re-elected as an independent in 2024. Momentum shrinks to just over 10,000 members (2024) and in 2026 is still organising inside Labour; Corbyn co-founded Your Party, which adopted a collective leadership and elected him parliamentary leader in March 2026.

Three layers, one campaign

The 2017 campaign was not the party's alone. Researchers describe it as an official campaign surrounded by satellite campaigns the party did not control.

• The partyOfficial Labour and the leader's team: the manifesto, rallies, a Facebook page with policy videos and positive messages, and local branches' canvassing.
• The satelliteMomentum: mobilisation tools, persuasion training, carpools, harder-edged videos for young people, the reminder cascade. Separate from the party, with its own lists and channels.
• The networkThousands of volunteers with no title, carpool and WhatsApp groups, commentators such as Owen Jones and Paul Mason in the videos, and Corbyn-friendly blogs that spread the content.

What was specific to the UK in 2017, and what you need to swap if your country works differently.

Platforms

Doorstep canvassing in marginal seats

The heart of the operation. Under first-past-the-post, a door in a seat decided by a few hundred votes is worth far more than a door in a safe seat. Momentum ran about 50 campaign weekends in those seats.

My Nearest Marginal

A site where you entered your postcode and found the nearest marginal seat, the actions planned there and who was offering or looking for a lift. By polling day, 100,000 people had used it.

Facebook

Where the videos ran. In 2017 Facebook prioritised video in the feed, and Labour's official page posted about 12 times a day, three quarters of it video. Momentum had about £2,000 for ads and bet on sharing.

WhatsApp

The channel for the polling-day “cascade”: a reminder message passed from person to person that, according to Momentum, reached 400,000 people, mostly young.

Peer-to-peer texting and a calling app

Texts sent by volunteers, targeted by area, to flag local actions, and a Momentum phone-banking app, a method borrowed from the Sanders campaign, for calling from home and asking people to pledge part of 8 June to the campaign.

Rallies and livestreams

Corbyn's rallies filled squares and stadiums and were streamed on Facebook. The Birmingham one, on 6 June, had 2.3 million views by the close of polls.

Slack and carpool groups

Slack for people leaving the training who kept organising; carpool groups on Facebook, like the one used in the 2019 Peterborough by-election.

Local conditions

• A short snap election: called on 18 April for 8 June, seven weeks. The Conservatives started with a 21-point poll lead.
• First-past-the-post in 650 seats: the national result depends on a few dozen marginals. According to Emma Rees, eleven were decided by fewer than 100 votes.
• A new mass party: after 2015 Labour passed half a million members, and many activists lived in big cities where Labour was already strong. Hence the idea of moving them to the marginals.
• A satellite organisation: Momentum was formally separate from the party, with its own lists and channels. That gave it freedom to innovate, for example with carpools, and to use a tone the official campaign would not approve.
• Internal tension: part of the party machine and of the MPs was hostile to Corbyn. A 2018 book claims HQ staff spent about £5,000 on ads seen only by the leader's team.
• A press largely hostile to the Labour leader, which pushed Labour and Momentum towards their own channels.
• Unequal spending: in the 12 months before the election, the Conservatives spent £18.5 million and Labour £11 million, according to official returns.
• Two terror attacks (Manchester, 22 May; London Bridge, in early June) suspended campaigning for days and put security at the centre of the debate.
• Individual voter registration: over 1.1 million people aged 18 to 35 registered after the election was called, which made registration part of the mobilisation.

Momentum did not try to be a second party. It did three things the party did not do well: move people, train people and produce content that spread without money.

Three fronts

Move the base to where the vote is decided

Most activists lived in safe seats. A simple site (postcode, nearest marginal, planned action, lift) turned that concentration into a mobile force.

Persuasion at the door

Rather than only identifying who already voted Labour, volunteers learned to listen, isolate the main concern and answer with the right policy. The method came from people who had worked on the Sanders campaign.

Own content that spreads

Short, satirical, cheap videos made for young people to share, and person-to-person WhatsApp reminders on polling day. Almost no paid ads.

The campaign cycle

For seven weeks the same cycle ran non-stop: each campaign weekend fed the next, and the final stretch turned everything towards polling day.

1. Map List the marginal seats where the gap is within reach of volunteer effort and keep the data up to date. A data lag led to accusations of favouritism early on.
2. Call out Open the tool to anyone, not just members: 100,000 people used the site, four times Momentum's membership.
3. Train Sessions several times a week, with role-play: empathise, isolate the concern, answer with the right information.
4. Transport Carpools and group travel to take people from safe seats to marginals, with campaign weekends set well in advance.
5. Talk Doorstep canvassing in the marginals, calls from home through the app and texts about local actions.
6. Tell the story Short satirical videos for people who don't read party manifestos, with a call to vote on the day and a link.
7. Get out the vote A public pledge to take the day off, doors all day in the marginals and a WhatsApp reminder cascade.
8. Retain and scale After the vote: new members, a national training network and a digital volunteer network. Rees's lesson: distribute roles so you don't depend on three staff.

And again.

What Momentum built, organised for you to copy. It works best in constituency-based elections, but the logic (take trained people to where each contact counts most) serves any campaign.

What works anywhere and what depended on the UK in 2017.

Choose your country

Pick the moves that fit your context and add them to your kit.

1. Send the base to where the vote is decided

   A simple finder answers every volunteer's question (where do I go, when and with whom): postcode, nearest marginal seat, scheduled action and a lift. In the UK, 100,000 people used My Nearest Marginal, four times Momentum's membership.

   How to set it up, step by step

   Works when

   It works when the result hinges on a few seats, neighbourhoods or towns and your base lives bunched up where you have already won.

   Don't use when

   It fails with out-of-date seat data, which breeds accusations of favouritism, or when the central team does not answer people who volunteer.

   1. Week −7 List the marginal seats where the gap is within reach of volunteer effort
   2. Week −7 Build the finder: a map, a sheet of actions and a lift-share form
   3. Week −6 Name a local lead in each target seat to welcome people who arrive
   4. Week −6 Open the tool to anyone, not just members
   5. Week −5 Schedule campaign weekends in advance, with departures from the big cities
   6. Week −1 Text people by region about the next action near them, where and when
   7. D-day week On polling day, send everyone available to the tightest seats

   Team

   • National coordination: picks the target seats and the calendar
   • Digital tools: keeps the finder and its data up to date
   • Lifts and travel: matches people offering and needing a seat
   • Local hub: welcomes volunteers, hands out streets and collects results

   What to measure: Volunteers who actually turned up at an action in a marginal seat, counted by the local lead, not just those who signed up.

   Risks to watch: Lifts and doorsteps expose volunteers: identified drivers, pairs on the doors, one contact person per group and a harassment protocol.

   Add to my kitIn my kit

2. Persuasion-conversation training

   Instead of only counting who already votes your way, volunteers learn to listen, acknowledge the worry, isolate it and answer in ten seconds with the right policy. Momentum trained more than 3,000 volunteers in over 40 sessions, with trainers from the Sanders campaign.

   How to set it up, step by step

   Works when

   It works when there are undecided voters to win over and someone with real door-knocking experience to train trainers.

   Don't use when

   It fails as a recital of the manifesto, or when the training depends on four people and stops when they tire.

   1. Week −7 Bring in trainers with experience from another campaign, union or movement
   2. Week −6 Write the script: introduce, listen, empathise, isolate, answer, ask, record
   3. Week −6 Schedule three or four open trainings a week, with role-play
   4. Week −5 Put everyone who leaves a training into a group for the next actions
   5. Week −4 Train new trainers from among the most active volunteers
   6. Week −2 Review the sheet: most-heard worries and the answers that worked

   Team

   • Trainers: design the training, run the role-play and train new trainers
   • Group coordination: takes people from the training to their first action
   • Data: compiles the worries heard and feeds them back to trainers

   What to measure: Full conversations logged on the sheet per trained volunteer, with the main worry recorded.

   Risks to watch: Political opinion is sensitive data: keep the minimum, restrict access and delete it after the campaign.

   Add to my kitIn my kit

3. Polling-day leave and a reminder cascade

   A public pledge to take polling day off becomes the day's rota, and a ready-made message passes from person to person on WhatsApp, to people's own contacts only. In 2017, nearly 10,000 people took the pledge to take polling day off; by Momentum’s own account, relayed by the New Statesman, they knocked on more than 1.2 million doors.

   How to set it up, step by step

   Works when

   It works in the final weeks, when people are willing to give a full day and personal networks exist where a friend's reminder carries weight.

   Don't use when

   It fails with bought lists or mass messaging without consent, which are unlawful, or if no one turns the pledges into a rota.

   1. Week −3 Open the pledge page: take the day off or give a shift on polling day
   2. Week −2 Turn the pledge list into the day's rota, seat by seat
   3. Week −1 Write the cascade message: date, where to vote, an invite and a request to pass it on
   4. Week −1 Remind everyone who pledged and confirm meeting point and time
   5. D-day week On the day: doors from early morning in the marginal seats
   6. D-day week Release the cascade in the morning and phone from home for those who cannot travel
   7. 1 week(s) after After the vote, invite everyone who took part to stay in the network

   Team

   • Pledges: runs the page and the list of who took the day off
   • Rota: assigns people by seat and by shift
   • Messaging: writes the cascade and the phone-from-home script

   What to measure: Pledges kept: people who turned up for their assigned shift on polling day.

   Risks to watch: Messages without consent breach GDPR and similar laws: the cascade only works if each person writes to their own contacts.

   Add to my kitIn my kit

4. Cheap satirical video with a date and a link

   Short videos with one idea and one emotion, shot cheaply and ending with the polling date and a link, made for young people to share. Momentum had about £2,000 for ads and bet on sharing by real people.

   How to set it up, step by step

   Works when

   It works when the press is hostile, there is no ad budget and the audience you want does not read party manifestos.

   Don't use when

   It fails if the satire invents facts, or if an aggressive tone puts off the undecided voters the campaign needs.

   1. Week −6 Set up a small writing and filming team
   2. Week −6 Write each video with one idea, one emotion and a clear ending: date and link
   3. Week −5 Check every fact before posting: exaggerate the situation, never the facts
   4. Week −4 Post on the network your young audience uses and ask people to share
   5. Week −1 In the final week, switch the ending to the call to vote and a where-to-vote link
   6. D-day week On polling day, repost the video that converted best

   Team

   • Writing: scripts one-idea videos and checks the facts
   • Filming and editing: produces cheaply and fast
   • Social: posts, tracks link clicks and asks real people to share

   What to measure: People who, from the video's link, checked where to vote or registered, counted with a tracked link.

   Risks to watch: Satire that invents facts is disinformation and burns credibility: always say who is publishing, and no fake profiles or bought accounts to spread it.

   Add to my kitIn my kit

Momentum's sequence adapted for a seven- to eight-week campaign, as a checklist. Your progress is saved in this browser.

A satellite group has no party machine behind it, only the trust of the people who follow it.

Say who publishes

All material (video, site, leaflet) should identify who is responsible. Momentum's 2017 pages carried the name of the person promoting them on the organisation's behalf.

Third-party rules

Many countries limit and require registration of groups that campaign outside the party, and add coordinated spending to the candidate's. Check the law before you spend.

Consented contacts only

The cascade works because each person writes to their own contacts. Buying lists or mass messaging without consent is banned by the GDPR, Brazil's LGPD and similar laws.

Satire with true facts

Exaggerating a situation is humour; inventing a fact is disinformation. Every video should survive a fact-check.

Real people only

No fake profiles, bought accounts, bots or anonymous pages to spread the videos. Momentum's reach came from real people sharing. Coordinating real people to say what they think is allowed; what platforms punish is organizing likes, follows or hashtags to game the algorithm. X, for example, bans trading engagement and using a trending hashtag to manipulate the conversation.

Canvass data

Political opinion is sensitive data. Keep the minimum, with restricted access, and delete it after the campaign.

Safety in carpools and on the doorstep

Identified drivers, pairs on the doorstep, a contact person for each group and a harassment protocol.

Honest numbers

Publish your figures and say where they come from. Claiming wins without basis, as in Sheffield Hallam, creates friction with your own allies.

It didn't win the election

Labour came second, 64 seats short of a majority. The method helped strip the Conservatives of their majority, not form a government.

It didn't repeat in 2019

With about twice as many people on the doorstep, according to Rees, more staff, a better tool and 106 million views, Labour fell to 202 seats. Mobilisation doesn't make up for an unfavourable political context.

The digital effect is unproven

Researchers say the digital success of 2017 was more proclaimed than demonstrated. The reach figures are Momentum's own.

There was no youthquake

The British Election Study found no rise in youth turnout; Labour gained votes across almost all ages. Don't attribute the result to the youth videos alone.

The satellite tone has a cost

Studies of Momentum's page point to memes, partisan content, leader adoration and aggressive posts. That mobilises engaged young people and can put off the undecided voters the official campaign wanted.

It depends on a leader and a faction

The energy was tied to Corbyn. With the change of leadership, Momentum lost weight, fell to just over 10,000 members in 2024 and saw part of its base leave for other parties. Faction shapes the tools too: early in the campaign, My Nearest Marginal was accused of steering activists away from Corbyn-critical MPs such as Neil Coyle; it was soon resolved and put down to slow data updates. Whoever decides where volunteers go also decides who gets help: publish your targeting criteria.

The central team becomes a bottleneck

In 2017, many volunteers went unanswered. Without distributing roles, the energy is lost.

Five questions to confirm the essentials.

This playbook was built from Momentum's own pages, interviews with organisers and trainers published between 2017 and 2019, academic studies of satellite campaigns and Facebook in 2017, and official election data. All pages were accessed on 26 October 2026.

Updated 26 October 2026