Boris Johnson floated the idea of building another transport link across the Channel during a UK-France summit, it has emerged.
The Foreign Secretary, who was among top Cabinet ministers to meet their French counterparts at Sandhurst military academy on Thursday, is understood to unveiled his plan during the talks.
Sources close to the Foreign Secretary told Sky News that Mr Johnson said: “We need a new fixed link between UK and France.
“It’s crazy that two of the biggest economies in the world are connected by one railway line when they are only 20 miles apart.”
Sky News also understands, from British sources, that French President Emmanuel Macron replied: “I agree, let’s do it.”
During Thursday’s summit, Mr Johnson – a leading Brexit supporter – had hailed the “important work” taking place.
He posted on Twitter: “I’m especially pleased we are establishing a panel of experts to look at major projects together.
“Our economic success depends on good infrastructure and good connections.
“Should the Channel Tunnel be just a first step?”
He later posted a picture of himself and Mr Macron both making a thumbs up gesture.
It was reported that Mr Johnson had specifically spoken of a potential bridge across the Channel.
Industry groups have poured scorn in the idea of a bridge across the Channel.
Jonathan Roberts, communications director at UK Chamber of Shipping, told Sky News: “Building a huge concrete structure in the middle of the world’s busiest shipping lane might come with some challenges.
“The Government and the EU should concentrate on keeping trade moving freely through our ports, something which is in the economic interest of both sides, instead of searching for headline grabbing ideas that sound better on paper than they would be in practice.”
In his recent book “Fall Out”, Sunday Times’ political editor Tim Shipman claimed Mr Johnson had previously touted a road tunnel between the UK and France.
The Foreign Secretary was quoted as saying: “If you wanted to show your commitment to Europe, is it not time for us to have further and better economic integration with a road tunnel?
“You could come out of the EU but join Europe in the most fundamental way.
“You undo the damage done at the end of the Ice Age.
“The Channel is really a river whose tributaries used to be the Seine and the Thames.
“It became bigger and bigger and bigger as the ice melted until it separated Britain from France.”
Shadow foreign secretary Emily Thornberry responded to the idea in a post on Twitter: “I ignored this earlier because I assumed it wasn’t real. Apparently it is. I mean…who are these clowns claiming to run our country?”
The UK Chamber of Shipping also posted: “Building a huge concrete structure in the middle of the world’s busiest shipping lane might come with some challenges.”
Prior to the building of the Channel Tunnel, opened in 1994, the prospect of a road bridge between Britain and France had been considered.
A submission for a £3bn three-lane motorway link was made to transport officials in 1981, according to the National Archives.
Over the past decade, China has built some of the world’s longest bridges, with the cross-water Jiaozhou Bay link spanning more than 25 miles.