Andy Burnham has once again sent Labour’s Blairite backbenches into a storm. The wannabe Prime Minister has a knack for infuriating his party’s ‘right’ and today is no exception. His latest wheeze? Signing up to a ‘progressive rally’ in East London, where he’ll be parked alongside such political luminaries as former Green leader Caroline Lucas and Lib Dem grandee Sir Vince Cable.

The Change:Now event, slated for the end of this month, is choc-a-bloc with trade union barons, left-wing think tankers and even the director of an organisation dedicated to ‘building migrant power’. Ministry of Housing minister Miatta Fahnbulleh, an Ed Miliband acolyte, also makes the bill. Talk about a grand coalition: from the left to the, er, even more left…

Lucky attendees are promised a ‘day of debate, disagreement and deliberation between progressives of all parties and none’. Burnham backers get to discuss ‘what policies we need to deliver the change to reset our economy and the political and cultural changes we need to bring about those policies’. Irresistible stuff.

Less enthused are Labour’s embattled moderates, already watching their grip on the party unravel at a rate of knots. In a burst of irritation, they’ve now accused Burnham of undermining campaign efforts ahead of the local elections. Luke Akehurst, a loyal defender of Sir Keir Starmer, fumed:

Anyone in the Labour party who has been advancing the concept of a progressive alliance involving the Greens should surely be reconsidering this at the moment, given the revelations about the extent of antisemitism amongst their council candidates.

Burnham himself has kept quiet about his starring role, though an ally has leapt to his defence in – where else? – the Guardian: ‘It’s ridiculous to suggest Andy is supporting other parties. He is advancing progressive ideas to help the Labour party.’ Sure. Just as his frequent interventions on Sir Keir have been solely about party unity, not, you know, personal ambition.