Prime Minister Keir Starmer’s grip on power has been thrown into further jeopardy today following explosive reports that a significant faction of left-wing Labour MPs are actively preparing to defect to the Green Party if Andy Burnham fails to oust Starmer from Number 10.

The revelation introduces a chaotic new dynamic into the upcoming Makerfield by-election, framing the June 18th contest not just as a regional battle, but as the potential trigger for a historic splintering of the Labour Party.

The Makerfield Catalyst and Burnham’s Bid

The political establishment is acutely focused on the Makerfield by-election, where Greater Manchester Mayor Andy Burnham is currently leading polls (at approximately 43%) against strong right-wing opposition from Reform UK and Restore Britain.

Burnham’s entry into the parliamentary race is widely viewed as a precursor to a direct leadership challenge against Starmer. Prominent Labour figures are speaking openly about this transition. Speaking at the Hay Festival, Labour MP Jess Phillips stated plainly, “I imagine Andy Burnham will win it, and I imagine then that he’ll be the Prime Minister of the country.”

However, the new crisis for Downing Street centers on the contingency plan being drawn up by Labour’s left flank should Burnham’s bid fail.

The Defection Threat: Labour to Green

Political commentary channels, including British Stand, highlighted breaking reports this morning that senior left-wing Labour backbenchers—reportedly including Clive Lewis (Norwich South) and Richard Burgon (Leeds East)—are prepared to cross the floor and join the Green Party if Burnham loses the by-election or fails to trigger a successful leadership contest.

The threat indicates that the roughly 100 Labour MPs who have reportedly expressed a desire to remove Starmer are not willing to simply fall back into line if the Prime Minister survives the immediate crisis. Instead, they are willing to blow up the party’s parliamentary arithmetic.

A Green Party source confirmed the overtures, telling the media: “We are [more] interested in winning elections than defections; however, we know that more and more Labour voters and politicians recognize the Green Party as the most authentic party of the left.” The source crucially added, “We will always talk with anyone who shares our values,” effectively leaving the door wide open for disgruntled Labour MPs.

A “World of Pain” for Starmer: Two Disastrous Scenarios

The defection threat places Starmer in an unwinnable strategic position, creating two highly destabilizing timelines following the June 18th vote:

• Scenario A (Burnham Wins): Burnham successfully gains the Makerfield seat and immediately initiates a leadership contest. Given Starmer’s current polling deficit and internal party unpopularity, Burnham would be the heavy favorite to win, resulting in Starmer’s immediate ouster from Downing Street.

• Scenario B (Burnham Loses): Burnham fails to win the seat. While Starmer might survive a subsequent, weaker leadership challenge from figures like Wes Streeting or Angela Rayner, he would face immediate mass defections from his left flank to the Green Party. This would decimate Labour’s working majority and leave Starmer leading a fractured, hostile, and severely weakened minority government.

The Prime Minister’s strategy of trying to “carry on, ignore it, and hope that it disappears” is rapidly disintegrating. The Makerfield by-election has ceased to be a simple test of local popularity; it is now the fulcrum upon which the survival of the current Labour government rests. With left-wing MPs actively exploring an exit strategy, Starmer is facing the imminent reality that even a tactical victory over Andy Burnham could trigger the structural collapse of his parliamentary party.