Wycombe MP Steve Baker has urged his fellow Tory MPs to put in no-confidence letters in Theresa May’s leadership to reach the 48-letter mark that would trigger a formal challenge.

The former Brexit minister turned staunch opponent of the Prime Minister, suggested that that Mrs May had a "duty" to stand down in order for a new leader to deliver EU withdrawal.

"What I would like to happen today is for Conservative Members of Parliament to realise that we simply cannot go staggering forward any longer like this and I'm afraid to put their letters of no confidence in," Mr Baker told BBC Radio 4's Today programme.

But Mrs May's spokesman responded: "The Prime Minister believes it is her duty to deliver on the will of the British people and take us out of the EU."

The European Research Group (ERG) of which Mr Baker is deputy chairman, has been calling for MPs to move against the Prime Minister for weeks by sending letters to Sir Graham Brady, chairman of the backbench 1922 Committee of Conservative MPs.

Mr Baker told Today: "Of course, we have all taken a bit of a bruising on this and it is a grave decision for every colleague to make.

"But what I would say to my colleagues is: you now face the certainty of failure with Theresa May, you must be brave and make the right decision to change prime minister, and change prime minister now."