When the Foreign Secretary discussed the potential construction project following a day of immigration talks the French leader reportedly responded: “I agree. Let’s do it.”

Mr Johnson put forward his idea as Theresa May and Emmanuel Macron sealed a deal that will fast-track asylum applications at Calais.

The former Mayor of London tweeted: “So much important work in United Kingdom-France Summit outcomes, but 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?”

Mr Johnson is understood to have discussed a privately-funding bridge or tunnel link joining the two nations with his French counterparts.