BORIS JOHNSON suffered another blow last night as former Tory cabinet minister Sam Gyimah made a surprise defection to the Liberal Democrats.

Mr Gyimah, who represents East Surrey, made an unannounced appearance at the Lib Dems’ annual conference with party leader Jo Swinson.

In an exclusive interview for The Observer, he accused Mr Johnson of “veering” the Tories towards “populism and English nationalism,” and said that he made the decision to defect in order to fight the government’s “scorched earth approach” to Brexit.

Mr Gyimah, who was once considered a rising star in the party under former prime ministers David Cameron and Theresa May, was one of the 21 Tory MPs who had the whip removed for voting to block a no-deal Brexit.

As a rising star in Ms May’s government, Mr Gyimah infamously filibustered a Lib Dem-sponsored Bill that would have automatically pardoned all gay people who had been historically convicted under “indecency” laws.

He is the sixth MP to defect to the Lib Dems this year, following former Change UK MPs Chuka Umunna, Luciana Berger and Angela Smith and former Tory MP Phillip Lee, and brings their number of parliamentarians to 18.

The move is expected to bolster the party’s current strategy of winning over anti-Brexit Tory voters in Remain Tory areas, and comes as the party’s conference voted to revoke Article 50 and cancel Brexit without risking a second referendum, which might go the same way as the first and confirm the Leave vote.

Writing in yesterday’s Observer, Ms Swinson said: “The Liberal Democrats are the strongest Remain party in the UK, and we continue to grow, adding members, councillors and MPs.

“When a general election comes, we will be ready for it and ready to take our clear, pro-European message to the country.”

Labour shadow justice secretary Richard Burgon said: “The Lib Dems have become home from home for disgruntled Tory politicians.

“Not a surprise when the Lib Dems showed their true colours by becoming a key part of Cameron’s austerity-imposing government.

“Unlike the Lib Dems, Labour stands for real change for the many not the few.”