UK Prime Minister Boris Johnson is pushing ahead with plans for a bridge between Northern Ireland and Scotland.

The bridge would reportedly be constructed across the largest munitions dump in the world.

One retired offshore engineer in 2018 described the project as being “as feasible as building a bridge to the moon” adding that “no sane contractor or responsible government” would attempt it.

Sources inside Downing Street confirmed to Business Insider that Johnson remained personally committed to the project, despite doubts about its viability.

Visit Business Insider’s homepage for more stories.

UK Prime Minister Boris Johnson is deadly serious about building a bridge connecting Scotland with Northern Ireland and is preparing to give the project the green light.

The prime minister has previously said a bridge connecting the two countries across the North Channel would be a “very good” idea, despite warnings about cost and unexploded bombs dropped in the sea after World War II.

Now Johnson has instructed civil servants to look at how the project can be delivered and is awaiting an official assessment on whether it is feasible.

A representative for Johnson said on Monday that “work is underway” on the project, adding that “it’s an idea that the prime minister has expressed interest in in the past, and as he said at the time, ‘Watch this space.'”

They added that government officials were carrying out a “proper piece of work” on the proposal.

Downing Street sources confirmed to Business Insider that Johnson remained personally committed to the project despite doubts about its viability expressed both inside and outside the government.

Lees ook op Business Insider 28 winkels dicht bij ketens Miss Etam, Claudia Sträter, Expresso en Steps – 200 banen minder bij doorstart

‘As feasible as building a bridge to the moon’

Foto: The Oresund Bridge in Sweden is reportedly the inspiration for Johnson’s proposed bridge from Northern Ireland to Scotland.sourceNurPhoto/NurPhoto via Getty Images

Officials reportedly think the bridge could be based on the Oresund Bridge, which connects the Swedish city of Malmo with Amager, an island near Denmark’s capital, Copenhagen.

Officials working on the plans have produced a route from Larne in Northern Ireland to Portpatrick in Scotland.

Reports have suggested that the construction would be part bridge and part tunnel, to avoid unexploded bombs in the water. Beaufort’s Dyke, 7 miles off the Scottish coastal village of Portpatrick, is the site of tonnes of rockets, metal drums, and radioactive waste dumped there following World War II.

The project is estimated to cost about £20 billion, but costs could spiral because of the need for connecting infrastructure on either side of the bridge.

The UK Chamber of Shipping said that while it welcomed “any initiative which seeks to improve trade and tourism links,” Johnson’s plan to build a bridge across the North Sea was “unnecessary.”

A spokesperson said: “There are already a range of ferry operators taking tourists and trade between Northern Ireland and Scotland.

“Spending £15 billion-£20 billion of taxpayers’ money on a bridge simply to replicate what those ferries already do is unnecessary. The money could be far better spent improving road and rail links to our ports across the UK.”

Johnson first suggested the idea of a bridge across the Irish Sea when he was the foreign secretary in 2018. He has revived it since entering Downing Street as part of his plans for major infrastructure projects across the UK.

His proposal was, at the time, branded by one expert as a “thoughtless soundbite” that “no sane contractor or responsible government” would sanction.

Writing in a letter to The Sunday Times, James Duncan, a retired offshore engineer from Edinburgh, said the idea was “about as feasible as building a bridge to the moon.”

“Many long bridges have been built, but none across such a wide, deep and stormy stretch of water,” he continued.

“For a great part of the 22-mile route the water is more than 1,000ft deep. It would require about 30 support towers at least 1,400ft high to carry the road deck across the deepest part and above the shipping channel. In total the bridge would require 54 towers, of heights never achieved anywhere in the world.”