UK Prime Minister's Position in Jeopardy: Who is the Frontrunner to Replace Him?

The position of the British Prime Minister, Sir Keir Starmer, is under considerable pressure. Less than two years after the Labour Party’s landslide victory in the general election, Starmer’s leadership is now being challenged from within his own party.

Starmer’s popularity has declined sharply following various shifts in political stance that have disappointed the British public. A significant defeat for Labour in local elections on May 7, 2026, has further intensified the pressure on him.

According to The Economist, nearly 100 of the 403 Labour MPs are reportedly calling for Starmer to resign. The pressure has increased after five ministers submitted letters of resignation, including Wes Streeting, the former UK Health Secretary.

Starmer has so far stated that he will remain in office. However, the possibility of a leadership contest within the Labour Party is now increasing. Under party rules, a new leader can be elected if 20% of Labour MPs formally express support for another candidate.

Several names have emerged as potential replacements for Starmer. These include Wes Streeting, Angela Rayner, Ed Miliband, and Andy Burnham, the Mayor of Greater Manchester.

According to the latest Betfair Exchange data cited by The Economist, Andy Burnham is now seen as the strongest candidate.

The odds of Burnham becoming prime minister have risen sharply to 54%. This is significantly higher than Angela Rayner at 16%, Ed Miliband at 8%, Wes Streeting at 7%, and the odds of Starmer remaining in office until the next election at 6%.

Burnham’s Path to Downing Street Will Not Be Easy

Despite being the favorite in prediction markets, Burnham’s path to 10 Downing Street is still long. He must first win a by-election to return to the House of Commons or the British Parliament.

After that, Burnham also needs to gather support from 81 Labour MPs to be able to compete in the party leadership contest.

Therefore, the timing of Starmer’s departure is still uncertain. According to Betfair’s prediction market, the highest probability of Starmer leaving his position is at the end of September 2026, which is 52.6%.

Meanwhile, the probability of Starmer resigning at the end of June is only 2.5%. There is also a 22.7% chance that he will remain in office until the end of December 2026, and a 22.2% chance that he will stay on until 2027 or later.

Makerfield Will Be an Important Test

Burnham’s fate will largely depend on the by-election in Makerfield, Greater Manchester. On May 14, 2026, Josh Simons, the Labour MP for Makerfield, resigned to make way for Burnham.

The Labour Party then allowed Burnham to run as a candidate in the area on May 15, 2026.

Historically, Makerfield has been a strong base for Labour. Since the constituency was formed in 1983, Labour has always won and never received less than 40% of the vote in national elections.

However, this time the challenge is not easy. Reform UK managed to gain about 50% of the vote in the Makerfield local council election on May 7. This makes Labour’s position not entirely secure.

The Betfair prediction market estimates the probability of Labour winning in Makerfield at 55%, while Reform UK is at 43%. The odds for Labour could still change if Burnham’s candidacy is officially approved.

Labour Members Prefer Burnham

If Burnham manages to enter parliament, his chances in the internal Labour contest will be quite high. The party’s membership base of around 250,000 people tends to lean left and many come from the public sector.

In a Survation poll of Labour members on May 13-14, 2026, Burnham was far ahead in a direct comparison with Starmer.

A total of 61% of Labour members said they would vote for Burnham, while Starmer received only 28%.

Other candidates could also defeat Starmer, but the difference is smaller. Ed Miliband received 46% against Starmer’s 39%, while Angela Rayner received 45% against Starmer’s 41%.

Meanwhile, Wes Streeting trailed far behind. He only received 23%, while Starmer led with 53%.

Burnham is the Most Liked, But It May Not Be Enough

In terms of public popularity, Burnham is also one of the Labour figures with the most positive image. A YouGov poll on May 12-13, 2026, showed that Burnham has a higher approval rating than several other Labour figures.

However, the challenges remain significant. Burnham has been away from Westminster for almost a decade to lead Greater Manchester. This means that for some national voters, he may not be a widely known figure.

On the other hand, Labour is currently still behind in various polls. A change of leader may not immediately improve the party’s chances in the next election.

The key lies in the ability of the new Labour leader to offer a clearer political direction and regain voters who have left the party in the last two years.

With the current conditions, Andy Burnham is indeed the strongest candidate to replace Keir Starmer.

However, before he can truly aim for the position of prime minister, Burnham must pass two major tests: winning in Makerfield and securing strong support from Labour MPs.