Labour has been plunged into bitter recrimination as traditional supporters turned their backs on appeals to vote for Britain to Remain in the EU.
With the overwhelming majority of Labour MPs backing In, there was raw anger as it became clear the vote had gone against them.
MPs complained the party was “out of touch” as its traditional northern strongholds such as Sunderland, Rochdale and Oldham voted comfortably for Leave
Frontbencher Chris Bryant turned on former leader Ed Miliband, whose overhaul of the party’s rule book was widely seen to have paved the way for Jeremy Corbyn’s election as leader.
“I might go and punch him because he’s a T****** and he left the party in the state it’s in,” he said.
Mr Corbyn, a long-time Eurosceptic, defended his conduct in the campaign amid criticisms that he offered no more than lukewarm support for Remain, blaming Government austerity cuts for alienating voters.
“A lot of the message that has come back from this is that many communities are fed up with cuts, they are fed up with economic dislocation and feel very angry at the way they have been betrayed and marginalised by successive governments in very poor areas of the country,” he told BBC News.
“The point I was making was there were good things that had come from Europe in working conditions and environmental protections but there were other issues that had not been addressed properly.”
But backbencher John Mann, who switched to back Leave in the final weeks of the campaign, said the party was paying the price for ignoring the concerns of working class people on issues such immigration.
“Labour has gone wrong by not being in touch with its voters, I’ve been saying this for the last 10 years in relation to immigration and free movement of labour,” he told BBC News.
“I’ve said it for the last 10 years repeatedly and what we’re offering working class people, what the country’s offering, is zero hours contracts, agency work, insecurity, and people are sick to death of it, they’ve had enough.
“And that’s why, in my area and elsewhere, Labour voters have voted in huge numbers to leave the European Union.”
Mr Mann, one of Mr Corbyn’s fiercest critics in the party, acknowledged he would carry on as leader but said he had to “get out there talking to these voters, which he hasn’t been doing”.
Shadow international development secretary Diane Abbott, one of Mr Corbyn’s closest allies, insisted his natural scepticism towards the EU meant that he was well-placed to take the party forward after the referendum.
“Jeremy Corbyn’s position on Europe, which was always sceptical, was always closer to the national mood than any other party leader,” she told BBC News.
“That puts him in a strong position to be a voice for working people as we go forward into these negotiations.”
Shadow chancellor John McDonnell, another close ally of Mr Corbyn, echoed his leader in blaming Tory austerity cuts for voter concern on immigration, arguing the Government has cut the NHS and failed to provide enough school places.
But that drew a scathing response from Labour MP John Woodcock who said: “If that’s our conclusion then Labour is toast.”