Labour should ignore right-wingers who “hate blacks, hate women and hate gays” in order to win a second referendum campaign to stay in the EU, Paul Mason has said. 

The former advisor to John McDonnell said the party should stop trying to convince the “ex-miner sitting in the pub calling migrants cockroaches” to change their mind – and instead focus on inspiring progressive or centrist voters.

It comes in the wake of a disastrous European election for Labour, which saw Jeremy Corbyn’s party haemorrhage support to the Greens and Liberal Democrats.

Many within the party have blamed the party’s refusal to take a pro-second referendum and pro-Remain stance for the drop in support. 

Mason also turned his fire on party chairman Ian Lavery, who, he claimed, told members a second Brexit vote would be used as “a weapon to overthrow Jeremy Corbyn” – something denied by Lavery. 

Lavery, and fellow shadow ministers, had shown a “sentimental understanding of working class politics” and “can’t bear the idea of right-wing thought in their communities”, he said. 

He also claimed Momentum activists outside failed to campaign during the Euro-elections.  

The deep divisions within Labour emerged as all parties anticipate the election of a new Tory leader resulting in either a snap general election or fresh Brexit referendum as early as this year. 

Mason, who was speaking at an event on the future of the pro-Remain left at the London School of Economics, said Labour should use the summer to embark on a ‘stop Brexit’ tour of Britain by organising “conventions of progressive people”. 

He added: “And if people who hate blacks, hate women, hate gays, don’t want to come to them – don’t bother. 

“Don’t worry about it. They can go off and do their own thing. We need Labour to bring in the Greens, the Lib Dems and the millions who didn’t vote over.”

He added: “I’m done with triangulation, not only with right wing voters. I’m done with triangulation from members of the shadow cabinet.”

He added: “I’m done with people saying ‘we can’t lose the working class’, a Lithuanian nurse is working class, an Afghan taxi driver is working class. 

“An ex-miner sitting in the pub calling migrants cockroaches has not only no added human capital above the people I just mentioned but it’s also not the person we are interested in.” 

It comes after Mason and Lavery became embroiled in a Twitter spat in the immediate aftermath of the Euro-elections result. 

Mason added: “Members refused to give out leaflets, because they thought they were written by Tom Watson or Alastair Campbell to attack Corbyn. Our own members didn’t campaign. 

“The people who campaigned inside Labour outside London in all these towns were the Labour right. I’ve asked Momentum: what did you do?” 

Momentum’s national organiser Laura Parker, who failed to get elected as an MEP for Labour in London, was also at the event.

She accused Jeremy Corbyn of overseeing a “cavalier” and “insulting” campaign with “crap leaflets” that focused on “bobbies on the beat” rather than EU issues. 

“We clearly didn’t have anything to say on the big issue of the day,” she told the event at the London School of Economics.

She added: “[Labour] kept saying we were going to unite the country. I know we are only one party and we are in opposition, but what have we done in the last three years to try and unite the country. 

“Moreover, what have we done to try and unite the party. How can we make a ‘unite the country’ pitch when we have to unite our own party first?” 

Parker also suggested Labour’s “vision-free” campaign returned a “frankly embarrassing” result and that it deserved to lose ground to the Green Party. 

“We shied away from this election, it was vision free,” she said.

Shadow business minister Chi Onwurah admitted Labour’s Euro-elections campaign had failed to inspire voters. 

“Given the collection of shambles that goes by the name of the Tory Party, our results should have been a lot better and would have been a lot better if we had been clearer on where we stood on a final say,” she said.  

She went on to say Corbyn’s Brexit policy should be dictated by members.  

“We cannot be party in any sense to a no-deal Brexit,” she said. “I would also say that it has to be part of our party’s values to reflect our members’ values and position and our membership is overwhelmingly for a final say referendum.” 

She added: “People have the right to vote to be poorer and that can be for whatever their reasons are, but that has to be done explicitly, and now that we understand what a no-deal Brexit means.” 

HuffPost UK has approached Ian Lavery for comment.