THE proposal for a “Celtic Bridge”, first unveiled by The National in January 2018 and followed up by media organisations across the world, has united nationalist and Unionist politicians on both sides of the Irish Border and on both sides of the Irish Sea.

Irish Prime Minister 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.

READ MORE: No 10 still keen on ‘Boris Bridge’ to Ireland to cement Union

The Prime Minister has confirmed that work is now under way on a feasibility study.

A road and rail crossing between Portpatrick and Larne is architecturally possible and would boost tourism and trade for both sides of the crossing, while providing an extra needed physical link after Brexit.

The National:

A major challenge that would need to be overcome is Beaufort’s Dyke: a deep-sea trench around 300m 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. There they are using the concept of floating bridges to overcome the depth.

Norway has a population similar to Scotland and is in the process of investing £30 billion to create the Norwegian Coastal Highway, a 1100km route from Kristiansand in the south to Trondheim in the north. The road will cross 20 fjords, some more than 600 metres deep, using floating bridges and tunnel connections.

READ MORE: Angry 'Boris Bridge' architect says idea is no ‘fantasy'

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.

Another possible route for the bridge is between the Mull of Kintyre and Torr Head on the Antrim coast, which are just over 12 miles apart.

A comparison with the Oresund Bridge (below) can be made here. It connects Copenhagen in Denmark with Malmo in Sweden. Copenhagen has a population that is comparable to Glasgow’s and Malmo’s with Edinburgh. The Oresund Bridge was the result of a collaboration by both countries, each with a distinct, proud history but who “share a Nordic cultural heritage”.

The National:

More than 25 million people use the crossing each year and the bridge has made a £10bn return on the initial investment since its opening 18 years ago. It has established the Oresund Economic Region which employs four million 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.

READ MORE: Nicola Sturgeon says bridge funding should be sent to Holyrood

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 £15bn 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.

The National:

Professor Alan Dunlop (above) FRIAS FRSA is a Glasgow-based architect and visiting professor of architecture