Around 2.6 million voters have switched their support from leaving the EU to remaining, major new polling shows.

Around a million voters have switched their support in the other direction, meaning a net total of 1.6 million more voters now support remaining in the EU compared to 2016.

Campaigners say it adds pressure on the government to arrange a new Brexit referendum.

LONDON — More than 2.6 million voters have abandoned their previous support for Brexit and now support remaining in the EU, according to new polling.

When offset by the 970,000 people that have switched their support from Remain to Leave, that would mean a net total of 1.6 million more voters now support remaining in the EU compared to the 2016 vote.

The polling was carried out by YouGov for the pro-EU group Best for Britain who hope to add pressure on the government to legislate for a "People's Vote," or a new referendum, on the final terms of any Brexit deal.

The majority for Leave in 2016 was approximately 1.3 million, meaning a second referendum would be even more closely-run the 2016 vote.

Analysis of the polling also recorded a shift in support for Remain across the UK, with 112 constituencies switching from major Leave-supporting to supporting Remain. There has been a shift towards Remain in 93% of constituencies, and 341 seats now favour staying within the EU, with 291 wanting to Leave.

More data from the poll is due to be released on Wednesday.

Labour's Brexit dilemma

Labour leader Jeremy Corbyn Christopher Furlong/Getty

Many backbench Labour and Conservative MPs have voiced their support for a fresh EU referendum in recent months. But both parties have consistently opposed such a move, with Theresa May insisting that such a move would be "a gross betrayal of our democracy."

Labour leader Jeremy Corbyn also opposes a new vote and is concerned that support for a new vote would hamper their chances at the ballot box among Leave voters.

But analysis of the polling found that large numbers of Leave-supporting Labour voters are in fact switching their support to remain, with 1.4 million of the 2.6 million who switched their support from Leave to Remain counting themselves as Labour voters.

Labour MP David Lammy, a supporter of the Best for Britain campaign, said: "Labour members, Labour voters and many Labour MPs remain strongly pro-European.

"Our leadership needs to wake up and smell the coffee, by supporting a people's vote on the final deal."