The Labour Party is bracing for a potential leadership contest, effectively triggered by Andy Burnham's announcement to stand in the Gorton and Denton by-election. This move, seen as his first step in challenging Sir Keir Starmer's leadership, marks the culmination of months of strategic manoeuvring by the Manchester Mayor, which included assessing support among Labour MPs. His team claims to have secured backing from over 100 MPs, surpassing the minimum 81 required to stand for the party leadership, indicating a significant base of support for his ambitions.

Burnham's prospective bid is bolstered by key alliances. A deal was reportedly struck with Angela Rayner before Christmas, promising her the Deputy Prime Minister role if Burnham's campaign is victorious. Rayner's public backing was instrumental in building momentum within the Parliamentary Party. Additionally, informed sources suggest that Ed Miliband, who expressed hope for Burnham's candidacy in Gorton and Denton, would serve as Chancellor in a Burnham government.

However, Burnham faces numerous hurdles before he can launch a full leadership challenge. First, he must navigate the resolve of Sir Keir Starmer's allies, who are intent on blocking his return to the Commons. Labour's ruling National Executive Committee (NEC), which is majority-controlled by Starmer's loyalists, will decide whether to permit Burnham to resign as Manchester Mayor and stand in a parliamentary election, as party rules dictate. This decision is complicated by concerns over the financial cost of a second by-election to replace him as Mayor (estimated at £4.7 million for the last one) and the risk of Reform UK capturing the mayoral post in Greater Manchester.

Furthermore, Burnham must actually win the by-election itself, which could be challenging given Labour's general unpopularity in some areas and the strong presence of Reform UK in the North-West. Nigel Farage has vowed to "throw everything" at the contest, despite Burnham's private polling suggesting he would win due to the local demographic. Burnham could also face challenges from the Greens' Zack Polanski and the Workers Party of Britain's George Galloway, potentially splitting the left-wing vote. If he secures the seat, he will also need to reconcile his past denials of a return to Westminster with his immediate leadership ambitions, with many expecting an initial show of loyalty followed by a challenge in July, capitalizing on potentially disastrous local election results.

The leadership race is unlikely to be a one-horse affair. Health Secretary Wes Streeting has been accused of running a "shadow campaign" for months, with Westminster insiders believing he has had a leadership operation "ready to go" since late last year. He has made no secret of his ambition for the top job. Home Secretary Shabana Mahmood is another Cabinet Minister widely tipped for Downing Street, having impressed Labour MPs and the public with her "no nonsense" approach. She has openly admitted her ambition, stating, "You should not believe anyone in politics who says they are not ambitious about the top job, because they are basically lying to you." There are suggestions that Mahmood might make her bid before Streeting. Her current role as chairman of the party's ruling NEC could also play a significant role in blocking Burnham's path to becoming an MP, a move that would reportedly appeal to Streeting.

Angela Rayner's political trajectory is closely tied to these developments. After being forced to resign as Deputy Prime Minister and Housing Secretary just four months ago over tax issues, she is poised for a dramatic return to government if Andy Burnham becomes Prime Minister. She is expected to regain her Deputy Prime Minister post and a plum Cabinet role as a reward for her backing of Burnham. Rayner, who consistently tops polls among Labour members and is popular among MPs, had previously denied wanting the top job, but her allies have reportedly been preparing for a tilt. Her public endorsement was a crucial factor in building momentum for Burnham's campaign within the Parliamentary Party.