Boris Johnson’s Channel bridge proposal: ‘It would cost less to move France closer’

Boris Johnson’s plan for a 21-mile bridge to link Britain and France is “entirely feasible” but could be scuppered by a £120 billion price, experts believe.

Engineers claimed that a crossing linking Dover to Calais was achievable because of huge advances in technology and the design of suspension bridges in recent decades.

Yet they warned that the cost, possibly more than twice that of the HS2 railway line, would probably be prohibitive.

Mr Johnson, the foreign secretary, raised the prospect of a bridge as it was announced that Britain and France were setting up a panel of experts to look at joint infrastructure projects. President Macron is said to have replied: “I agree, let’s do it.”

Downing Street appeared to pour cold water on the idea, saying that there was no plan for the bridge, and Mr Macron’s office dismissed as “nonsense” claims that he had endorsed the plan, while admitting “the issue of access is an important one”.

The bridge, which would have to cross the world’s busiest shipping lane, with 500 vessels passing each day, was criticised by maritime chiefs.

Jonathan Roberts, communication director at the UK Chamber of Shipping, said: “A huge bridge across the Channel would pose considerable difficulties for safe navigation. Ninety-five per cent of the UK’s international trade is moved by sea, so we need to make shipping operations easier, not harder.”

Alan Dunlop, from the school of architecture at Liverpool University, pointed to the £12 billion cost of the new 34-mile sea bridge linking Hong Kong and Macau. “That’s without any regulation, processes, health and safety and using Chinese workers,” Professor Dunlop said. “I’d say at least £120 billion for a Channel bridge and that’s a conservative estimate. It would really be cheaper to move France closer.”

Ian Firth, past president of the Institution of Structural Engineers, said technology had moved on from the 1970s when a bridge was considered before the Channel tunnel was built.

“It is entirely feasible. Before the tunnel was built there were bridge options being looked at,” he said. “There are bridges of a similar scale elsewhere. It would be a huge undertaking, but it would be absolutely possible, and shipping impact issues could be dealt with.”

Christian Bocci, senior partner at Weston Williamson, the architects behind infrastructure projects including Crossrail and the Jubilee Line, said that “the Channel tunnel has been a great success and is now at capacity; the principle to establish another connection route between France and UK is a good one. This kind of blue-sky thinking is to be encouraged because without it we can forgo real progress in collective human endeavour. We shouldn’t sniff at these ideas, but relish the chance to design these innovative structures.”

Charlie Elphicke, the Conservative MP for Dover, said: “Boris is right. We absolutely must invest in infrastructure to keep trade flowing between Britain and France.” A bridge across La Manche was proposed in 1981 as an alternative to the Channel tunnel project then being considered by the Thatcher government. A three-lane motorway would have been carried 220ft above the sea on a 21-mile suspension bridge. Engineers were forced to concede that the 15 huge pylons required could make navigation of the Channel difficult and eventually the government opted for the tunnel, which was completed in 1994.