More than 100 Westminster constituencies that originally voted to leave the EU, have now turned on their orignal stance—and have switched their support to remain, according to a major recent analysis  by the Observer. The study concluded that most seats in Britain now contain a majority of voters who would rather stay in the EU than leave – in findings that could have a major impact on the parlimentary battle of Brexit later this years.

The analysis suggested that the shift had been driven by doubts among labour voters who backed leave originally. The trend is most observable in the north of England and Wales, the labour heartlands in which the sentiment appears to be changin. This development will further pur pressure on Jeremy Corbyn to soften the party’s opposition to reconsidering Britain’s EU departure.

The research was compiled by modelling two YouGov polls of more than 15000 people total—conducted before and after British prime minister Theresa May published her proposed Brexit deal on July 6. The polls were combined with the detailed census information and data from the Office for National Statistics to come to the conclusion.

A total of 632 seats in England, Scotland and Wales were examined for the study. It was found that 112 had switched from leave to remain. The new analysis suggested there are now 341 seats with majority remain support, up from 229 seats at the referendum. One seat has switched support in Scotland and 97 have switched in England, while 14 of the 40 seats in Wales have changed from leave to remain. Overall, the model puts remain on 53% support, with 47% backing leave.

Among the constituencies to switch from leave to remain, most significantly– is that of Boris Johnson, the former foreign secretary and face of the leave campaign itself. Support for remain in his Uxbridge and South Ruislip constituency has risen from 43.6% to 51.4%, according to the new model.

Surrey Heath, the constituency of the other Leave figurehead, Michael Gove, also emerged as having a pro-remain majority. Support for remain increased from 48% in 2016 to 50.2%. There was also a 12.8 point swing towards remain in shadow chancellor John McDonnell’s seat of Hayes and Harlington.

The seats of three pro-Leave Labour MPs switched to remain. Birkenhead, Frank Field’s constituency, now has a 58.4% majority in favour of remain. Graham Stringer’s Blackley and Broughton constituency now has a 59% in favour of remain. Kelvin Hopkins’s Luton North seat now has 53.1% backing remain.

Eloise Todd, the chief executive of Best for Britain, stated: “This groundbreaking research shows that Brexit is still not inevitable. People across the UK have witnessed the last two years of uncertainty with dismay and are thinking differently – 112 constituencies have switched to majorities that back staying in our current bespoke deal with the EU.

“The sands of public opinion are shifting and politicians risk falling behind. Our research shows that the deal must be put to the people. Westminster should legislate for a people’s vote on the Brexit terms, giving the public the option to stay and build our future on our current deal with the EU.” he added.