Labour deputy leadership: who could replace Angela Rayner and how the race reshapes Starmer’s project

Sep, 7 2025

The first in-government showdown since 2007

Angela Rayner’s abrupt resignation on 5 September has set off the most consequential internal Labour contest in years: a fresh fight for the Labour deputy leadership. It’s the first time Labour has run this race while in government since 2007, when Harriet Harman edged out Alan Johnson after John Prescott stepped down. The trigger this time is very different. Rayner quit as deputy prime minister and deputy party leader after revelations that she failed to pay the correct stamp duty on a home purchase. The political vacuum she leaves is immediate—and dangerous for a party still adjusting to the pressures of office.

For Keir Starmer, it’s a brutal test of control. Rayner wasn’t just his party deputy; she was his deputy prime minister, a public counterweight with independent clout since Labour’s 2024 election win. Her departure forces two decisions at once: who becomes Labour’s elected deputy leader, and how much power that person will actually wield inside government.

We’ll get the outline fast. Labour’s National Executive Committee (NEC) meets in an emergency virtual session on Monday to settle the contest rules and timetable. Party staff have already been working through scenarios—do they race through a ballot before or during party conference, or delay to keep conference focused on policy rather than a factional brawl? Internal elections always risk spooking a government in its first year. With memories of past splits never far away, the anxiety is real.

Expect a left-versus-centre dynamic, at least on the surface. The left and soft left see an opening to tug Starmer’s centrist project closer to their priorities. The party’s right wants a loyalist who will lock in message discipline and protect the leadership’s agenda. The comparison some MPs are making—grimly, and for a reason—is with 1981, when Tony Benn’s challenge to Denis Healey tore at Labour’s seams and helped usher in defections to the SDP.

One big twist: Starmer has already reshaped the government side of the equation. In a reshuffle designed to steady the ship, he named David Lammy as deputy prime minister. That move ensures continuity in cabinet but caps the leverage of whoever wins the party deputy job. You can see the logic from No 10: avoid creating a parallel power base. You can also see the risk: members might bristle if their elected deputy is sidelined in government.

The field: soft left momentum, centrist caution, and a party on edge

The shortlist isn’t final until the NEC sets nomination rules, but three names are already in the conversation across the soft left: Rosena Allin-Khan, Dawn Butler, and Emily Thornberry. Each brings a different pitch—and a very different relationship with the current leadership.

Rosena Allin-Khan is the likely frontrunner from that camp. The Tooting MP and A&E doctor came second to Rayner in the 2020 deputy race and has remained one of the most recognisable figures on Labour’s middle-left flank. She served as shadow minister for mental health and built a profile on NHS and social care issues that resonates with members. Allies say she’s been urged to run by MPs across the party’s soft-left and unaligned spaces. Her pitch would lean on unity and competence—less factional fire, more feel for public services and campaigning.

Allin-Khan’s challenge is practical: can she lock in the parliamentary nominations and the organisational muscle needed to win a fast, national campaign while Labour is in government and diaries are jammed with legislative business? She has name recognition with members but will need union and local party networks to snap into gear quickly if the NEC sets an aggressive timetable.

Dawn Butler is weighing a comeback too. The Brent Central MP, briefly a candidate in the 2020 deputy contest, has long been a go-to voice for Labour’s activist left. She’s direct, ideologically consistent, and known for taking fights to the government of the day—whether that was Boris Johnson’s Downing Street or, more recently, critics of Labour’s direction. Butler appeals to members who want a deputy with a spine and a clear moral compass. The question is breadth: can she expand beyond the core left and reassure anxious MPs who worry about reopening old wounds?

Emily Thornberry adds a different profile—establishment experience without current cabinet baggage. The Islington South and Finsbury MP served as shadow foreign secretary and ran for the leadership in 2020. When Labour entered government, she didn’t join the cabinet but avoided making public trouble for Starmer. Instead, she took on the Foreign Affairs Committee chair job and kept largely disciplined, at least until recent weeks, when she became more openly critical of the government’s domestic delivery. Thornberry would likely run as a bridge figure: serious on foreign and defence, credible on media rounds, and able to pressure the centre of the party without blowing it up.

Put bluntly, the left senses its “organise or die” moment. That’s how one soft-left source described it this weekend. With Rayner gone—and with No 10 moving quickly to consolidate authority through Lammy’s appointment—the race is less about titles and more about leverage. The new deputy can become the party’s internal fixer and the members’ voice at the top table. Or the role can be kept deliberately narrow, a message manager rather than a policymaker.

Where does the centre land? Some on the party’s right are still testing the water. A candidate with strong frontbench credentials could yet emerge, but several potential names are holding their fire while they wait to see the NEC timetable and the mood among unions. Without an obvious centrist standard-bearer, the soft-left lane looks less cluttered, which is exactly why Starmer loyalists are working the phones to line up parliamentary nominations for someone they trust.

The stakes aren’t theoretical. Veteran MPs remember 1981 vividly, even if the mechanics have changed. Back then, Labour used an electoral college that amplified union clout and parliamentary blocs. Today it’s one-member-one-vote with a preferential ballot—members, affiliates, and other eligible supporters rank candidates, and transfers decide the winner if no one hits 50% on first preferences. That tends to reward broad appeal. It also punishes campaigns that collapse outside their base. Any candidate who talks only to their corner of the party is asking to lose on later counts.

Another layer: unions. Their formal role is smaller than in the old electoral college days, but their organisational reach—money, digital lists, campaigners—still matters. A well-timed union endorsement can firm up credibility and help with turnout, especially if the contest runs over conference season when activists are already mobilised. Without that, candidates rely on local party officers and MPs’ private networks, which can be patchy.

Timing will be brutal either way. If the NEC keeps things tight, nominations could open within days, with hustings crammed around committee work, bill stages, and the run-up to conference. A longer contest avoids overshadowing conference speeches but risks weeks of shadow-boxing, leaks, and score-settling. Senior staff worry a noisy campaign could dominate headlines just as the government tries to land its next tranche of domestic reforms.

That’s why the architecture of the role matters so much. The deputy leader used to be joked about as a “non-job.” Not anymore. In modern Labour, the deputy is the protector, gatekeeper, fixer, and go-between: the person who smooths feuds, reassures unions, fronts hostile morning media rounds, and carries some political risk on behalf of the prime minister. Rayner did all of that, often while projecting her own brand. The new deputy will inherit the responsibility—just not necessarily the government title to match it.

Starmer’s options have been narrowing in real time. Before the reshuffle, he had three choices for the government side: leave the deputy prime minister post empty; create a “first secretary of state” role with similar weight; or appoint a straight deputy PM as a signal of stability. David Lammy’s promotion answers that, at least for now. It also changes the incentive structure inside the party. A left or soft-left winner may find their influence squeezed by a deputy PM who already has Starmer’s confidence and the machinery of government behind him.

That isn’t necessarily fatal to the party deputy’s power. Influence in Westminster comes from three things: control of process, command of the airwaves, and the ability to mobilise people. The deputy leader’s office can still decide who gets meetings, how disputes are escalated, which promises get tracked, and what feedback reaches the top. A sharp media performer can shape narratives even without a Whitehall brief. And a deputy who can turn out activists, calm union leaders, and keep marginal-seat MPs onside will always matter, title or not.

You can see the fault lines already. The left wants tougher commitments on public services, workers’ rights, and economic fairness—delivered at pace and with visible ownership from the party’s leadership. The centre wants to protect the government’s careful sequencing and avoid anything that spooks the markets or reopens the “tax and spend” fight before growth numbers improve. Both sides know a televised row in the middle of conference season would be a gift to the opposition.

There’s also a live risk that doesn’t come from the centre at all: defections to Jeremy Corbyn’s new party if a left candidate is routed and feels humiliated by the rules or the tone of the campaign. That threat is hard to quantify and easy to overstate, but it exists. The mere possibility is enough to give union leaders leverage and to nudge the NEC toward a ruleset that looks even-handed.

Here’s what to watch in the days ahead:

• The nomination threshold and route to the ballot. Recent contests have required a mix of MP nominations and support from local parties or affiliates. If the bar is set high or the pathway is narrow, that favours well-organised campaigns and squeezes outsiders.
• The timetable. A compressed schedule benefits candidates with pre-built operations—email lists, digital tools, endorsement lines, and media prep. A slower contest helps lesser-known names introduce themselves and test messages.
• Hustings format. Member-led Q&As and union events can change momentum fast. Expect pressure for in-person and virtual events to keep things accessible and high-energy.
• Discipline from campaign teams. Negative briefing is a turn-off in one-member-one-vote contests. The candidate who stays focused on delivery, competence, and values usually gains on second and third preferences.

What about the names again?

- Rosena Allin-Khan: Charismatic communicator with NHS credibility and a strong 2020 performance to point to. She can talk policy and retail politics, which plays well with members who want empathy and grit. Watch her early endorsements—especially from swing-seat MPs who value campaign craft.

- Dawn Butler: A clear left marker with activist energy. She speaks plainly about inequality and rights, which galvanises a base that wants sharper edges. The test is reassurance: can she persuade sceptical MPs that she’ll manage internal tensions rather than inflame them?

- Emily Thornberry: Experienced, media-ready, and plugged into foreign affairs. She offers competence and scrutiny without theatrics. If she runs, it will be to occupy a middle space—more hawkish on the world stage, more exacting about domestic delivery than No 10 might like—while promising to keep the show on the road.

There are other possibilities, of course. A centrist frontbencher could still be drafted if the leadership concludes the soft-left field looks too strong or too scattered. But every late entry pays a penalty in a modern internal election: organisation. Building a digital list, scripting messages, booking hustings prep, cutting broadcast clips—all that takes time. And time is the one thing this contest may not offer.

Meanwhile, the policy machine keeps grinding. The government is juggling its legislative programme, with departments under pressure to show early wins and avoid Whitehall drift. Allies of Starmer say the prime minister’s priority is simple: keep the governing project moving. That means no policy hostage-taking by any campaign, no freelancing on tax or spending, and no surprises for markets. The new deputy, whoever it is, will be expected to sign up to that discipline—and to help deliver it across a party that just lost one of its biggest internal enforcers.

There’s a memory hanging over all of this: 2007. Harriet Harman won the deputy race that year after a long, complicated contest with televised hustings and tight rounds. She then became a key operator for Gordon Brown through stormy times—not always aligned in tone, sometimes more outspoken than No 10 preferred, but central to the party’s ability to function. The job can be that again. But only if the campaign to fill it strengthens the party rather than tearing at it.

Rayner’s exit under a cloud of tax controversy is exactly the kind of moment that can trigger old reflexes: blame, factional calculus, point-scoring. The smarter instinct would be to treat the vacancy as a chance to reset how Labour talks to itself—and to the country—about delivery and fairness. Members will decide the deputy. Starmer will decide how much space that person gets. The outcome will tell us a lot about who’s really setting the pace inside Labour as it tries to turn a big election win into a governing project that lasts.

For now, all eyes are on the NEC call on Monday. The rules will shape the race; the race will shape the party. And the party, in government for the first time in more than a decade, can’t afford to look like it’s fighting itself when it should be fixing the country.