Jeremy Corbyn's ‘pro-Brexit’ approach is costing Labour tens of thousands of pro-EU supporters, party insiders claim.

They said the party has been ‘haemorrhaging’ support since the Labour leader said last month he would press ahead with Brexit even if he won a snap General Election.

One senior Labour figure is even privately telling colleagues that the party, which reportedly had 540,000 members last April, has shed more than 100,000 members in the past year – a figure disputed by party officials.

Labour leader Jeremy Corbyn is pictured at a rally in Hastings earlier this week. His ‘pro-Brexit’ approach is costing Labour tens of thousands of pro-EU supporters, party insiders claim

They declined to say how many members they now have. The claims emerged amid mounting anger from Remain-backing MPs who suspect Mr Corbyn will never support a second referendum.

They also came as Labour deputy leader Tom Watson told a Fabian Society conference in London the party was obliged to hold Brexit discussions with Theresa May ‘through our sense of patriotism and respect for democracy’ as long as the discussions were serious.

Mr Corbyn has so far refused to hold such talks and Mr Watson’s aides denied he was criticising his leader.

Shadow Brexit Secretary Sir Keir Starmer won cheers at the same event for saying a second referendum had to stay on the table.

Allies of Mr Corbyn, who failed to unseat Mrs May in a confidence vote last week, have insisted he is keeping faith with party policy on Brexit.

But pro-referendum Labour MPs – said now to number more than 100 – are expected to stage a formal protest tomorrow in favour of a second referendum.