Britain's Transport Secretary Grant Shapps has confirmed the British government is looking at the possibility of building a bridge or tunnel between Scotland and Northern Ireland as part of its review of connectivity within the UK.
It comes as an interim report by Network Rail boss Sir Peter Hendy, who is conducting a review of union connectivity, was published assessing ways transport can better connect all parts of the UK.
In the report, Sir Peter said he has asked two experts to lead a “discrete piece of work” to assess the feasibility of a bridge or tunnel between Northern Ireland and the British mainland.
The report set out how a UK Strategic Transport Network would deliver the ambition – upgrading direct transport links, reducing delays and stimulating growth across the four nations.
Mr Shapps told BBC Breakfast: "One of the elements in that review is should we have some sort of fixed connection - that could be a tunnel, it could be a bridge - between, for example, Scotland and Northern Ireland which is the closest crossing.
"Actually it is odd in a sense that we don't have a connection with another part of the United Kingdom so it is looking at whether that is feasible or not."
Mr Shapps rejected a claim by Scottish First Minister Nicola Sturgeon that money could be better spent than on building a link between Scotland and Northern Ireland.
Mr Shapps told the BBC: "I understand that it is not the responsibility of the Scottish First Minister to connect the United Kingdom together. The Scottish First Minister doesn't even believe we should be in a United Kingdom. So I understand her perspective but I think it is wrong.
"For example, if you live in Northern Ireland, you want to know that you can reliably get the hauliers and lorry drivers in with goods from the mainland of the British Isles.
"Why would you ever be against connecting different parts of our country in a better way? It shouldn't be a controversial thought at all.
"As one small part of this Union connectivity review (we will) undertake a study of the feasibility of doing that and we will report back in the summer."
British prime minister Boris Johnson has previously said work is under way to assess the feasibility of a bridge between Portpatrick and Larne - estimated to cost £20 billion.
Scottish First Minister Nicola Sturgeon has called for the money to instead be sent to Scotland and Northern Ireland to be spent on infrastructure projects.
Air passenger duty on domestic flights could also be cut under the plans to improve connectivity within the UK.
Mr Johnson said he wanted to “build back better” after the coronavirus crisis in a way that brings “every corner of the UK closer together”.
He will launch a consultation this spring on reforming air passenger duty.
