Penistone and Stocksbridge MP Angela Smith fears her party will be punished at the ballot box by voters in the region and slip behind the Tories into second place if Parliament ultimately votes for Brexit to go ahead.
The survey comes as Labour leader Jeremy Corbyn today uses a speech in Yorkshire to call on the Prime Minister to call a General Election to break the Brexit deadlock if, as expected, her Brexit deal is voted down by the Commons in the meaningful vote next week.
Labour took 49 per cent of the vote in Yorkshire and the Humber compared with the Conservatives’ 41 per cent in last year’s General Election, but an opinion poll of 2,000 people in the region conducted by YouGov for the People’s Vote campaign says this has already fallen to 44 per cent.
The campaign group says that with three-quarters of Labour voters in Yorkshire wanting the UK to stay in the European Union, its vote share is slipping as Remainers turn their backs on the party.
The poll suggests that if a Brexit deal eventually passes with the support of Conservative and Labour MPs, Mr Corbyn’s support across the region would slump to just 35 per cent
They would be four points behind the Tories, who would be on 39 per cent as support for anti-Brexit parties like the Liberal Democrats and the Greens surges.
Ms Smith said: “This poll is a real wake-up call for the Labour leadership and many of our colleagues.
“It shows that concern about losing Labour voters who backed leave in the last referendum if the party stands up to Brexit, is unfounded. In fact, if our party doesn’t stand up against Brexit, votes and seats across Yorkshire and the Humber are at risk.
“Labour members and supporters are overwhelmingly in favour of a People’s Vote with the option to remain in the European Union. But with only a few months until we crash out of the EU, our party is still sitting on the fence.”
In a speech in Wakefield today, Mr Corbyn will say that a general election is the most “practical” and “democratic” way to “break the deadlock” in Parliament over Brexit.
The Labour leader will argue that a government with a new mandate could negotiate a better withdrawal deal as he reiterates his call for another election.
Mr Corbyn is expected to repeat that his party will vote down the Prime Minister’s Brexit deal, and will explain Labour’s approach to unite Leave and Remain voters around their common interests.
He will say: “A government that cannot get its business through the House of Commons is no government at all. So I say to Theresa May: if you are so confident in your deal, call that election, and let the people decide.”
The Labour leader repeatedly pushed Mrs May to rule out a no-deal Brexit in the Commons yesterday as Europe dominated their exchanges at Prime Minister’s Questions.
The PM defended her Government’s efforts to prepare for the prospect of the UK leaving the EU without a deal and dismissed holding a general election.
She also attempted to ease concerns over Northern Ireland by insisting the Commons will get a vote on whether to extend the Brexit transition period or trigger the backstop if no trade deal is concluded by the end of 2020.
Mrs May highlighted apparent contradictions in Mr Corbyn’s approach to Brexit, adding: “The one thing we know about (Mr Corbyn) is his Brexit policies are the many, not the few.”
Young people in Leeds will get the chance to have their say on Brexit in a live debate on national television tonight.
Part of this evening’s Channel 4 News bulletin will be coming from the Rose Bowl building at Leeds Beckett University.
The debate, which is being hosted by Jon Snow, will feature an audience made up of 18 to 20-year-olds, who were too young to vote in the 2016 referendum but could take part if it was held today.
Leeds Beckett’s vice chancellor, Prof Peter Slee, said: “The broadcast from our Rose Bowl is just one example of the many ways our universities work to support local organisations.”