Labour Party leader and UK Prime Minister Keir Starmer has intensified a so-called 'Stop Burnham' campaign to counter a potential leadership challenge from Greater Manchester Mayor Andy Burnham, according to the source report. The conflict is set to erupt into the open if Burnham wins the Makerfield by-election scheduled for June 18. The by-election has become a de facto referendum on Burnham's leadership prospects, with polling giving him a ten-point lead over his Reform UK opponent.

The 10-point lead that threatens Starmer's hold

As the source details, polling shows Burnham holding a ten-point advantage over Reform UK in Makerfield, though the final result may depend on how right-leaning voters split between Reform and the minor Restore candidate. A Burnham victory would effectively hand him a mandate to challenge Starmer, whom he has long been seen as a potential successor to. Starmer's allies have been critical of Burnham's left-leaning economic proposals, framing the battle as one over Labour's ideological direction — centrist versus progressive.

The article notes that Burnham has essentially confirmed a win would prompt a leadership bid, though his supporters are divied on whether to move immediately or wait. starmer has been personally meeting with MPs to assert his resolve to remain in office, making clear he will not step down without a fight.

A televised clash on ITV's Peston reveals the depth of the split

The internal warfare spilled into public view when Culture Secretary Lisa Nandy and Labour MP Clive Lewis traded sharp words on ITV's Peston programme, according to the source. Nandy accused Lewis of 'breathtaking arrogance' after he commented on voter sentiment in Makerfield, noting that he had not visited the constituency while she represents the neighboring seat of Wigan. Lewis dismissed the national Labour brand as 'toxic' and argued that the by-election campaign is solely focused on Burnham's personal appeal.

This on-air confrontation underscores how personal and factional the conflict has become . Deputy Leader Angela Rayner's presence in Makerfield has fueled speculation about a possible political alignment with Burnham, though no formal pact has been declared. The frosty personal relationship between Starmer and Burnham reduces the likelihood of any negotiated settlement,the report says.

Burnham's fiscal rules evasion: a gift to Starmer's campaign

In a notable moment reported in the source, Burnham in a recent interview declined to specify the current fiscal rules, which opponents seized on as evidence of economic unseriousness. Starmer's team has reportedly planned a 'blizzard of activity' involving a suite of 'legacy' policies aimed at boosting his standing among MPs and neutralizing Burnham's economic platform. The question of whether Burnham can offer a credible national alternative to Starmer's centrist approach remains a key point of contention, with critics questioning the national applicability of his region-specific Manchester policies.

The article also notes that former Health Secretary Wes Streeting has signaled his own ambitions,potentially broadening the field if a contest materializes.

What happens if Burnham wins on June 18?

With the by-election date set, attention in Westminster is shifting to Burnham's next steps. According to the source, even if Burnham triggers a contest, Starmer could technically stand again without needing the usual 80 MP nominations, yet many doubt he would subject himself to the public scrutiny of summer hustings, which could be politically damaging. The 'Stop Burnham' effort is not only about defending Starmer's position but also about shaping the party's ideological direction. The outcome in Makerfield will signal the balance of power within Labour,setting the stage for a potentially turbulent leadership contest that could define the party's future.