Andy Burnham has accused Keir Starmer’s advisers of briefing against him instead of “pulling together for a Labour majority government”.
In a furious attack, the mayor of Greater Manchester blamed “unelected people in their 20s or 30s who think they know it all”.
He said he was the victim of anonymous attacks every time he tried to highlight the work he is doing in Manchester.
He told Times Radio: “Whenever I go out there with something positive, the negative Westminster briefing machine somehow flicks into gear.
“All that I’d say is leave me alone.”
Burnham, who served in government under Tony Blair and Gordon Brown when he was a Labour MP, added: “I honestly don’t know what purpose they think it serves. It would be nice to have some support from a national level.”
Burnham is a divisive figure among his former parliamentary colleagues after he refused to join the coup attempt against Jeremy Corbyn's leadership in 2016.
He has also angered many Labour MPs by repeatedly criticising Westminster, despite being a former special adviser, an MP for 17 years and a cabinet minister in three different departments.
Burnham insisted he did not blame Starmer or members of the shadow cabinet personally for the negative briefings.
He said: “I know who they are and you know who they are, the kind of people who, you know, the unelected people in their 20s or 30s who think they know it all and they’re the kind of bee’s knees. And they go around sort of briefing against elected politicians.”
Drawing parallels with the last time Labour came to power in 1997, Burnham said: “These anonymous briefers need to sort of go back to [1997] and learn from that, and make sure that as we kind of build from here we’ve got all sides of the party involved, respected and pulling together for a Labour majority government.”