Prime Minister Boris Johnson's plan to build a bridge from Northern Ireland to Scotland across an expanse of water where more than a million tonnes of wartime munitions were dumped have been branded lunacy by an Irish economist.
John FitzGerald pointed out the near-impossibility of building such a massive structure across a deep trench in the North Channel. "At the bottom of the Beaufort Dyke are a million tons of ammunition - including six-inch shells filled with phosgene gas," he said.
"If you stir that up, or even manage to put down a pillar and then a lorry goes across the bridge and it vibrates, you could set off an explosion. It's lunacy."
Large quantities of surplus munitions ranging from small arms to high explosives have been dumped in Beaufort Dyke, which is more than 50km long and 3.5km wide.
The precise locations and nature of the munitions were often poorly documented.
"Munitions were distributed over a wide area which extended outside the boundary of the charted dump site," a previous Scottish government report found.
Mr FitzGerald, son of former Taoiseach Garret FitzGerald, said the project would make no financial sense after Mr Johnson tasked civil servants with examining the feasibility of building such a structure which would be at least 12 miles long.
"The idea that this would come from Boris and nobody would point out the lunacy of it, I cannot understand," he added.
"The amount of traffic it would carry would be tiny relative to the Channel Tunnel."
The DUP has previously expressed support for the plan which has attracted interest from the Scottish government and Irish politicians.
But Fianna Fail's Brexit spokesperson Lisa Chambers said it will cost "a hell of a lot more" than the £15bn suggested by Johnson, while Sinn Fein leader Mary Lou McDonald has dismissed the idea as a distraction.
Jim Dale, senior meteorological consultant for British Weather Services, said the construction would be "fraught with hazardous weather and rough sea-related problems".
However, Sun columnist Jeremy Clarkson has championed the project. "Yes, it would be difficult to make," he wrote. "The seas there are rough and deep and the seabed is littered with discarded Second World War mines and bombs. But as John F Kennedy once said - we choose to go to the moon and do the other things not because they are easy, but because they are hard."
The former Top Gear host went on to compare Mr Johnson's backing of the plan to Labour minister Tony Benn's support for Concorde in the 1960s.
Residents and experts in the Mull of Kintyre, the most likely place where the bridge would end, have mocked the idea.
Eric Spence, trust manager at the Campbeltown-based South Kintyre Development Trust, told the Daily Record: "It would be shut for the vast majority of the year for high winds."