Keir Starmer appears to be facing the most serious threat yet to his position as Prime Minister, with growing unrest inside Labour fuelling speculation that a leadership challenge could now be approaching.

Pressure on Starmer has intensified following Labour’s poor local election performances, with several MPs publicly calling for him to step aside and three ministers reportedly resigning in protest at the party’s direction under his leadership.

While Starmer has managed to survive a series of damaging controversies in recent months, including the ongoing fallout surrounding the Peter Mandelson scandal, frustration within the party continues to grow. Questions over Labour’s electoral strategy, declining poll ratings and internal divisions have all contributed to increasing uncertainty around his future.

Despite mounting pressure, Starmer has so far resisted calls to resign. However, several senior Labour figures are believed to be positioning themselves for a potential leadership contest should the situation deteriorate further.

At the top of the betting market is Greater Manchester Mayor Andy Burnham, who is now the 4/5 favourite to become the next Labour leader. Those odds give Burnham an implied probability of 55.6%, underlining the growing belief among bookmakers that he could emerge as Starmer’s successor.

Burnham remains one of Labour’s most popular figures among both party members and voters, and his profile has only strengthened amid the current turmoil. The Mayor of Greater Manchester has repeatedly been linked with a return to Westminster, although a major obstacle remains: he is not currently an MP.

Labour’s National Executive Committee recently blocked Burnham from contesting the Gorton & Denton by election, meaning he would still require another MP to stand aside if he is to re enter Parliament and launch a formal leadership bid.

Speculation around Burnham’s intentions has continued to build in recent weeks, particularly after receiving public backing from former Deputy Prime Minister Angela Rayner. With pressure mounting on Starmer and bookmakers increasingly expecting change, attention is now firmly focused on whether Labour’s internal unrest could eventually trigger a leadership contest.