Remain supporters are “cave dwellers”, says Jacob Rees-Mogg

Asked at his speech in central London how he would have responded if Leave had lost the campaign, the bookmakers’ favourite to succeed Theresa May as Conservative leader said: “I had looked up that there was a Trappist monastery in Leicestershire.

“It was my intention to see if they would accept a visit from me, not on a permanent basis but at least an interim basis because I thought, that line of Attlee to one of his ministers ‘a period of silence on your part would be welcome’ would be something the winners would have been entitled to expect.”

Earlier, at a separate pro-Europe event organised by Open Britain, former EU commissioner Lord Patten took a swipe at Mr Rees-Mogg, who he said he had known since he was eight, saying: “The thing about Jacob is that he is much better than he has allowed himself to seem.

“It is all very well having those views and being thought to be rather an eccentric but interesting lad when you are eight. But having the same views when you are 48 raises, I think, one or two eyebrows.

“And, I think, he has allowed himself a bit to be taken over by his own image and caricature.”

Lord Patten called for the Irish border issue to be handled “very carefully” in Brexit negotiations as he said he did not want to see a return to violence.

The former Cabinet minister, who chaired a commission into policing in Northern Ireland as part of the peace process, said: “I really do think we have to be very careful about the way we handle this issue.

“For me it’s one of the examples of the recklessness of the ideological campaign to get us out of the European Union at all costs.

“I feel emotionally very strongly about this. I think we did a really good job on the Good Friday Agreement. And I don’t want to go back to the days when people were being shot and maimed.”

He also said Brexiteers were seeing their red lines diluted, stating: “Red lines are turning pink, or disappearing entirely.

“The Brexiteers swallow one slice of dogma pie after another.

“They are trying to put lipstick on what they used to call a pig – or at least a vassal state.”

Mr Rees-Mogg responded to Lord Patten’s comments at his own event, saying he did not want to “lay into” Lord Patten but criticising his stance on Brexit.

He said: “Lord Patten is a very old family friend and I’ve known him since I was an infant when he lived very near us in Somerset.

“He was very kind to me when I was out in Hong Kong and he was governor.

“So I don’t want to lay into his lordship. I will only say this, when he was governor of Hong Kong I greatly admired his efforts to defend and promote the rights of the people of Hong Kong and to argue for democracy.

“It is a great sadness that he wanted democracy for the people of Hong Kong but rejects it for the people of the United Kingdom.”

Prominent pro-Europe Labour MP Chuka Umunna used the Open Britain event to attack his front bench for “parroting” the Tories on immigration, saying: “One of the things I cannot abide, and I find intensely irritating is, frankly, to hear the Labour front bench increasingly parrot what the Conservative front bench says about this issue – immigration and Brexit – and, increasingly, too many other issues.

“You need only look at the comments of Liam Fox’s shadow, Barry Gardiner, in respect of the Brexit issue, and you do wonder where is the opposition?”