Six Tory MPs will contemplate splitting from the Conservative Party unless it “changes its direction”, Tory grandee Ken Clarke has warned.

The Father of the House of Commons said the Prime Minister was “running the risk of losing moderates from her party” and was “simply acting at the behest of the extreme right wing of the party”.

Comparing the current woes of the Tories to the battles over the Maastricht Treaty, the former Chancellor said: “Not only is this a worse crisis than any of the previous crises I recall, it’s also by far the most ridiculous, it’s quite incredible to see such a state of affairs.”

The decision by eight Labour MPs to leave and form the Independent Group was, he said, “very foreseeable”,  adding that if Labour leader Jeremy Corbyn did not change “I think there’ll be more”.

Asked about the prospect of Tories joining, Mr Clarke told the Press Association: “Oh, I think it’s quite a possibility yes…I’ve no idea how many, but I can think of half a dozen who I’m sure will contemplate it unless our party changes its direction.”

“Lifelong Conservative” Mr Clarke said his party had changed since the EU referendum.

He said: “Its present continuing drift towards the right is going to lose it some of the younger members if it’s not careful. Unlike me they have political futures and careers and they have to consider long term whether they can continue to associate with a party that, at the moment, is so much dominated by its extreme right wing.

“We’re a mirror image of Labour – both parties have been broken into different factions, not just split in half by Europe and the gaps.

“The divisions are getting worse all the time.”

On deselections, the MP for Rushcliffe said: “If the zealots in both parties just start purging the MPs on the more moderate wing then British politics is going to go into sad decline.

“The strength of the British two-party system is that the two parties have always been such broad based churches, they are pre-packed coalitions.”

Mr Clarke warned that the Prime Minister’s approach to the Brexit negotiations since the historic defeat of her Withdrawal Agreement last month risked alienating some party supporters, adding her tactics were “completely incomprehensible and extraordinary”.

Asked if he envisaged if Mrs May could face Government resignations over the prospect of Britain leaving the EU on March 29 without a deal, he said: “Yes, if she doesn’t rule out no-deal.

“I’m not going to guess, I think quite a lot…cabinet and non-cabinet.

“There are people in the Government who are as discontented as I am at the absurd situation we’ve got into.

He said: “Theresa’s style since Christmas has been extremely annoying to people like me.

“Since that time the only negotiations she’s carried out are with the European Research Group (ERG). She keeps trying to find out what Jacob (Rees Mogg) and Boris (Johnson) will agree to and then trying to tell the Europeans that they’ve got to alter things to get the support of Boris and Jacob.

“It is the most peculiar way of proceeding as Boris and Jacob lead a faction, the ERG, which is a tiny minority in the House of Commons as a whole.”

He added: “The customs union she keeps ruling out, when it’s perfectly obvious we need to stay in a customs union, we keep the border open at Dover as well as in Ireland.

“She’s now moved far from that and is pursuing extraordinary fringe things at the behest of her extreme right wing backbenchers.

“There are a lot of Conservative MPs in Government and outside of Government who are utterly dismayed by the fact that the only serious negotiations she will have are with ERG.”

Former cabinet minister Mr Clarke advocated a substantial extension of Article 50 or revoking it, adding: “The Government’s got to get a body of opinion behind it, cross party that has a clear idea of the future relationship it wishes to negotiate.”

Mr Clarke, who once described Mrs May as a “bloody difficult woman” said she had been an ally in past coalition government battles but could be “extremely stubborn”, adding: “I just don’t understand how she’s allowed herself to get into her present rather frankly ludicrous position of simply acting at the behest of the extreme right wing of the party.”

He added: “I understand how desperate she is to maintain the unity of the party, but you cannot put that above the national interest and she’s running the risk of losing moderates from her party.”