The odds of embattled UK Prime Minister Keir Starmer being ousted by the end of July are soaring this morning...

...after Greater Manchester Mayor Andy Burnham won a decisive victory for the ruling Labour Party that delivers him a seat in Parliament and, with it, a pathway to challenge Starmer for his job.

Burnham was elected in a standalone contest for the constituency of Makerfield, in northwestern England, with a convincing 54.8% of the vote. He defeated Robert Kenyon from Nigel Farage’s right-wing Reform UK, who secured 34.5%, while third-placed Restore Britain registered just under 7%.

In a post on X, Starmer congratulated his rival on his victory.

Farage said he was “disappointed,” in a video posted after the result.

Addressing voters who left his party for Restore he asked:

A defiant Starmer said in response that he would run against Burnham in any leadership contest.

As Bloomberg reports, the prime minister’s fortunes have faded after he led his party to a dismal showing in the May locals, where Reform gained ground. In the aftermath, almost a quarter of Labour’s more-than 400 MPs called on Starmer to go.

Despite, Burnham's ruling out changing the government’s limits on borrowing if he were to gain power, in a bid to reassure investors about his fiscal plans, his win pushed Cable slightly lower and gilt yields notably higher:

 “With Burnham having made a statement win, the next few months will likely see domestic political risks dominating headlines in the UK and as a result markets pricing in real political risk premium,” said Megum Muhic, a strategist at RBC.

Burnham has the best (least worst) ratings of any major UK politician...

“The prime minister is now in political quicksand,” James Lyons, Starmer’s former director of communications, told Sky News.

“There is now a very good chance that Andy Burnham will be installed as prime minister without a contest,” he said, adding that the size of the win makes that more likely.

If Starmer steps down or is voted out by the Labour Party membership, the UK would usher in its fifth prime minister in less than four years.