Is the UK headed for a new prime minister?

These are troubled times for British Labour Prime Minister Keir Starmer. In July 2024, Starmer’s government swept to power on the back on a landslide win.

Labour won 411/650 seats in the parliament, and had a commanding 174 seat majority. Starmer was elected on a platform for “change”, but the most likely change at the moment is that he’ll be cast aside as prime minister.

Where has it all gone so wrong?

First, Starmer’s majority was both thin and created a paradox. While he has a strong majority of MPs, Labour only secured a record low of 33.7% of the popular vote (the Conservatives received a dreadful 23.7%, a resurgent Reform secured 14.3%, and the Lib Dems 12.2%). In short, British politics fragmented.

The paradox for Starmer is despite the majority, he was gifted a multitude of MPs who sit on very thin majorities, and on current polls, face electoral oblivion. Labour could be reduced to just over 100 seats. Many have nothing to lose, except their seats.

Second, Starmer and his government have made a series of mistakes, missteps and u-turns, which have eroded public confidence. Controversially, his government pledged a series of welfare cuts targeting the Personal Income Payments (PiP), which led to over 120 MPs signing a “wrecking amendment” to his flagship welfare bill.

In the context of pledges to increase defence spending, this was seen to be at the expense of some of the most vulnerable Britons. Likewise, Rachel Reeves, who casts herself as something of an iron chancellor (equivalent to the Australian treasurer), was forced to reverse her decision to cut winter fuel payments to pensioners.

Labour pledged not to increase a number of key taxes when elected in 2024. But Reeves is now suggesting she’ll have to break the tax pledge for the imminent budget.

Labour has also had to shift positions on a suite of other issues, including gender identity and the controversial issue of “grooming gangs” in the UK, which involves allegations of group-based child sexual abuse and exploitation that mostly occurred between the 1990s and 2010s.

Third, there have been personnel changes and issues. The resignation of popular deputy leader Angela Rayner was damaging, and her successor Lucy Powell was not the leader’s chosen replacement. Starmer has been drawing on New Labour stalwarts to steady his ship, but his pick of Peter Mandelson as US ambassador backfired spectacularly with his links to paedophile financier Jeffrey Epstein.

Fourth, the Labour prime minister has faced a series of structural economic problems that requires low and patient re-calibration. To give a sense of the challenge, when Tony Blair became prime minister in 1997, government debt as a share of GDP was a healthy 35%. By 2004 it was 96%.

Yet, critics argue that part of this is a problem of Starmer’s and Reeves’ own making, because their fiscal conservatism is seen to be overreaching. By accepting the National Insurance tax cuts of her Conservative predecessor, Jeremy Hunt, Reeves gave herself no wriggle room for spending commitments.

What would it take to depose Starmer?

Labour party rules stipulate a leadership contest can be triggered if 20% of Labour MPs back an alternative leader, up from 10% before 2021. Currently, this would require 81 MPs. Further rule changes mean the Labour leader can now be challenged at any time. To date, no sitting Labour prime minister has been removed as party leader.

Experienced British Labour MPs will be aware of the Australian experience, where Labor experienced particular turbulence from 2007-2013, with the change from Kevin Rudd to Julia Gillard and back to Rudd.

Rudd then introduced leadership rule changes to tighten up the process for changing the leader. For Australian Labor, the threshold is high, with a spill requiring 75% of caucus members when in government, and 60% when in opposition.

Risks and challengers

Any potential challenger to Starmer will be frantically weighing up the costs and benefits of forcing a change. While a new leader might enjoy a honeymoon period in the polls, they would quickly need to show deeper results if Labour is to have any chance of re-election at the 2029 general election.

Moreover, unless the leader wants to shift the current fiscal orthodoxy and engage in deeper structural reform, they’ll only present as a new face to the same problems Starmer is facing. Starmer has driven Labour to the centre, and the cohort of left and “soft-left” MPs are the ones most ill-at-ease with how the party is tracking.

Westminster politics is awash with rumours of manoeuvres from both the left and right of the party.

What seems to have backfired for Starmer are the background briefings against Health Secretary Wes Streeting. Streeting would have the backing of the right of the party, and is articulate where Starmer is not. Former deputy leader Angela Rayner has been lauded as a potential “stop Wes” candidate.

In the run up to the recent party conference, popular Manchester mayor Andy Burnham was routinely cited as a potential leader, but will need to find a parliamentary seat.

A “stalking horse” candidate might emerge, with Home Secretary Shabana Mahmood touted. Yet, the rise of Nigel Farage’s Reform Party and the prospect of a one-term government might be worth the risk for any challenger. For Starmer to hold on, he’ll need Reeves to deliver a strong budget, sort out discipline within Number 10, and hope for better local election results in May 2026.