Professor Alan Dunlop’s “Celtic Bridge” plan was first unveiled by The National in January 2018 and was followed up by media organisations across the world.

While it has won over the Prime Minister there is still a huge amount of scepticism about the obstacles that would need to be overcome. Here, writing exclusively for The National, Professor Dunlop explains his solutions.

THE proposal has united politicians on both sides of the Irish Border and on both sides of the Irish Sea. Irish premier Leo Varadkar, his deputy Simon Coveney, DUP leader Arlene Foster, Scottish Brexit Secretary Michael Russell and Prime Minister Boris Johnson have all given their backing to the plan. The Prime Minister has confirmed that work is now under way on a feasibility study.

A road and rail crossing from Larne to Portpatrick is architecturally possible and would boost tourism and trade for both sides of the crossing while providing an extra needed physical link after Brexit. A major challenge that would need to be overcome is Beaufort’s Dyke: a deep-sea trench around 300 metres deep which runs parallel to the Dumfries and Galloway coastline and was used as a dumping ground for explosives after the end of the Second World War.

However, a possible solution has been pioneered in Norway, using the concept of floating bridges, to overcome the depth and non-contact with the sea bed. Norway has a population similar to Scotland and is in the process of investing £30bn to create the Norwegian Coastal Highway, an 1100km route from Kristiansand in the south to Trondheim in the north. The road will cross 20 fjords, some more than 600m deep, using floating bridges and tunnel connections.

The Norwegian Coastal Highway is a pioneering and remarkable infrastructure project and a sign of confidence for a forward-looking innovative country. Scotland and Ireland surely can achieve the same.

READ MORE: Bridge from Scotland to Ireland could create 'Celtic powerhouse'

Another possible route for the bridge is between the Mull of Kintyre and Torr Head on the Antrim Coast which is just more than 12 miles apart. A comparison with the Øresund Bridge can be made here. The Øresund Bridge connects Copenhagen in Denmark with Malmo in Sweden.

Copenhagen has a population that is comparable to Glasgow and Malmo with Edinburgh. The Øresund Bridge was the result of a collaboration by both countries, each with a distinct, proud history but who “share a Nordic Cultural Heritage”.

More than 25 million people use the crossing each year and the Bridge has made a £10 billion return on the initial investment since its opening 18 years ago. It has established the Øresund Economic Region which employs 4m people.

The case for the Celtic bridge is not only about economic benefit to the Ayrshire and Antrim coasts or Cowal peninsula but also about establishing closer social, cultural and political relations between Scotland and Ireland in the shifting post-Brexit climate.

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Politics in Scotland, Ireland, and in the rest of the UK are in an extreme state of flux, with questions over Brexit, border controls, and even independence still to be answered. The political failure to grasp this opportunity would indicate a lack of vision and authentic leadership.

A Celtic Bridge will rebalance the over-concentration of power in the South of England and could bring extraordinary benefit to many areas. Governments across the British Isles now need to work together on a feasibility study into a £15 billion bridge connecting Scotland and Ireland. Research should be carried out to establish the economic and social benefits of the bridge and assess any geological and engineering challenges it would pose. The UK has the engineering and architectural talent and the capability to build this project. It would be a transformative economic generator and a world first.