Boris Johnson is just 'a nicer version of Donald Trump', says Ken Clarke

Veteran MP says voters are fed up with the EU campaign being turned into a 'leadership bid' for the former London mayor

Clarke says many pro-Brexit campaigners were more interested in toppling the PM than having an informed debate (Getty)

Voters are fed up with Tory critics of David Cameron turning the EU referendum campaign into "a kind of leadership bid for Boris Johnson", Ken Clarke has warned.

The veteran MP dismissed the former London mayor as a "nicer version of Donald Trump" leading a campaign based on immigration fears that were "about as relevant" to real issues as the controversial Republican's US presidential push.

He added: "I think Boris and Donald Trump should go away for a bit and enjoy themselves and not get in the way of the serious issues which modern countries of the 21st century face."

Pressed on his opinion of Mr Johnson, he said: "He is a much nicer version of Donald Trump but the campaign is remarkably similar in my opinion and about as relevant to the real problems that the public face."

He suggested many pro-Brexit campaigners were more interested in toppling the Prime Minister than having an informed debate about the merits of continued EU membership.

Mr Clarke spoke out following a weekend of Tory warfare in which backbenchers branded Mr Cameron "corrosive" and a "liar" as they openly plotted to try to oust him even if Remain achieves a narrow win in the referendum.

Arch-Cameron critic Nadine Dorries predicted the Prime Minister would be "toast" even if Remain edged a win in the June 23 referendum and said she had tabled a letter seeking a no-confidence vote.

Fellow Brexiteer MP Andrew Bridgen insisted more than the 50 colleagues needed to trigger such a poll were ready to move against the PM.

They broke ranks as Mr Johnson branded Mr Cameron "corrosive" over his failure to meet a pledge to reduce net migration into the UK to the tens of thousands.

Mr Clarke repeated his view the party leader's authority would be "destroyed" and he would have to step down if the referendum was lost.But he called for an end to in-fighting ahead of June 23.

"His authority will be destroyed and, as we can see, half the campaigners are campaigning because that is their principal hope. Who will succeed him I haven't the foggiest notion," he told BBC Radio 4's Today.

"It is no good turning the leave campaign into a kind of leadership bid for Boris Johnson and anti-immigrant fears.

"The public are getting fed up with Tory civil wars when they thought they were being asked about the future of this country for their children and grandchildren.

"All this stuff about whether one or two backbenchers have signed letters calling for David Cameron to resign, I think most of the public would agree, is a bit of a diversion.

The show of cross-party unity with Mr Khan comes just weeks after Mr Cameron lambasted the Labour figure's "poor judgement" during the bruising battle for City Hall.

The mayor defended his decision to share a platform with Mr Cameron - despite Labour MPs shouting the Prime Minister down in the Commons as a "racist" when he attacked the now mayor - because he said Remain was in London's interest and he did not want to hold grudges.

Number 10 dismissed the personal attacks as a "distraction" intended to move attention away from the economic arguments for remaining in the EU.

Press Association