A BRIDGE between Scotland and Ireland could create a “Celtic powerhouse” and cost a fraction of the one proposed by Boris Johnson between England and France, a leading architect has said.

Professor Alan Dunlop, from the school of architecture at Liverpool University, said a combined road and rail crossing could be erected between Portpatrick, in Dumfries and Galloway, and Larne in Northern Ireland.

He said the new structure would boost the Scottish and Irish economies and help solve any longer term disputes over the re-emergence of an Irish border post-Brexit. He spoke out after the Foreign Secretary raised the prospect of a bridge over the English Channel last week.

In an interview with The National Dunlop said a bridge between Scotland and Ireland would make considerable more sense than Johnson’s idea.

“A bridge between Scotland and Northern Ireland would be an excellent idea,” he said.

“In terms of a crossing between Scotland and Northern Ireland, a Celtic Connection, the coastline between each country is more sheltered and the waterway better protected [than the English Channel].

“Crucially, the North Channel of the Irish Sea is not nearly as signif-icant a shipping lane.”

Dunlop added: “To propose a bridge between Scotland and Ireland would in fact be a big step in actually creating a “Celtic Powerhouse” and give politicians the opportunity to invest in the infrastructure of the true north. It might even prevent London and the south east from sinking into the Channel under the weight of investment in that region.

“Brexit is an interesting wrinkle as a bridge might help with the debate about customs, borders and access to the European market.”

Dunlop said a suspension rail and road bridge like that which connects Denmark and Sweden across the Oresund Strait could be built from Portpatrick to Larne, although he warned that Beaufort’s Dyke, a 300- metre deep sea trench off this stretch of the Scottish coast, would be a challenge for engineers.

“A combined sea and suspension railway and road bridge much like that which connects Denmark and Sweden across the Oresund Strait could work. The part above the dyke would have to float but be tied to the bottom, much like an oil rig,” he said.

Dunlop said that technically it would be easier to build a bridge between the Mull of Kintyre and Torr Head on the Antrim Coast. They are just over 12 miles apart and the sea is shallower, However, he warned it might not attract a sufficient number of vehicles because of the four-hour drive to Mull of Kintyre from the central belt.

He went on to say that a bridge would be better than a tunnel, although more expensive.

“A bridge is much better than a tunnel for it is a dramatic, visual marker for the aspirations and ambition of a country in the 21st century and beyond,” Dunlop said.

“You could potentially see it from Whitehaven, the Lake District and the Isle of Man, but it would be much more costly because of the geological and environmental challenges. However, it would also reinvigorate the area around Stranraer, potentially the Ayrshire coast from Troon to Stranraer and the whole north coast line of the Solway for people coming from the north of England.”

Dunlop estimated that the cost of the “Celtic Connection” bridge would be around £15 billion to £20bn – considerably less than his estimate of £120bn for the English Channel bridge.

Speaking at the end of last week about Johnson’s idea for the bridge over the English Channel, Dunlop said: “I’d say at least £120bn for a Channel bridge and that’s a conservative estimate. It would really be cheaper to move France closer.”

Johnson 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. French President Emmanuel Macron is said to have replied: “I agree, let’s do it.”

But Downing Street appeared to pour cold water on the idea, saying there was no plan for the bridge, and Macron’s office dismissed as “nonsense” claims he had endorsed the plan.

The English Channel 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, of 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.”

A bridge across the English Channel was proposed in 1981 as an alternative to the Channel Tunnel project then being considered by Margaret Thatcher’s government.