Jeremy Corbyn has signalled that he could restore Labour's historic commitment to the public ownership of industry if he succeeds in his bid to become party leader.
The veteran left winger has suggested he would consider reversing Tony Blair's decision two decades ago to scrap Clause IV of the party's constitution which committed it to "common ownership of the means of production".
The highly symbolic move was widely seen as a key moment in Mr Blair's leadership, helping to convince voters that the party could be trusted again in government after the wilderness years of the 1980s.
Jeremy Corbyn would consider bringing back the controversial Clause IV
In an interview with The Independent on Sunday, Mr Corbyn suggested he could consider bringing back the original Clause IV as part of a commitment to take back some "necessary things" into public ownership.
"I think we should talk about what the objectives of the party are, whether that's restoring the Clause IV as it was originally written or it's a different one, but I think we shouldn't shy away from public participation, public investment in industry and public control of the railways," he said.
"I'm interested in the idea that we have a more inclusive, clearer set of objectives. I would want us to have a set of objectives which does include public ownership of some necessary things such as rail."
Such a move would be every bit as symbolic as Mr Blair's original decision, marking a final break with the New Labour era.
Liz Kendall - the leadership challenger seen as being the closest to Mr Blair's policies - fiercely condemned the idea as a throwback to the failed ideas of leftwingers like the late Tony Benn.
"This shows there is nothing new about Jeremy Corbyn's politics. It is just Bennism reheated, a throwback to the past, not the change we need for our party or our country," she said.
"Life had moved on from the old Clause IV in 1994 let alone 2015. We are a party of the future not a preservation society."
With Mr Corbyn's campaign continuing to gather momentum, the Labour supporting Sunday People has come out in favour of shadow health secretary Andy Burnham in the leadership contest as the one candidate capable of stopping him.