Video report by Tim Backshall
The Scottish Secretary is calling for major work to upgrade the A75 through Dumfries and Galloway to start immediately.
Alister Jack met with business leaders in Northern Ireland today to discuss improvements to the route, which leads to the Cairnryan ferry port.
The Scottish Government though says transport is its responsibility and the UK Government should respect that.
Mr. Jack, the Dumfries and Galloway MP toured a ferry this morning this morning. He's trying to push the process. forward and believes the response by the Scottish Government has been slow.
"I think we want to start working immediately," he told ITV Border. "Rather like freeports, where we engaged with the Scottish Government and now we have a policy for freeports, we want to engage with them on union connectivity and what we can do now to upgrade the A75 with bypasses at Springholm and Crocketford and other measures that could be taken."
The poor state of the A75 - an important Euroroute - has led to a political dispute between the two governments.
The Scottish Government said in a statement:
"The Union Connectivity Review was set up without meaningful consultation with the Scottish Government. Transport is devolved to Holyrood, and the UK Government should respect that."
On the ferry from Cainryan to Belfast we heard of some of the problems that people encounter as a result of the predominantly single-carriageway roads leading to the port on the Scottish side. Lorries have to stick to 40 mph on much of the A75 and A77 roads.
"Personally I think the government need to upgrade it, create more passing lanes, " said one passenger from Dumfries and Galloway. "If they can't make it dual carriageway create more passing lanes."
His wife told us: "My family think twice about coming to see me because of the road."
"The travel time is far too long," added a passenger from Northern Ireland and one man who'd travelled from Newbury said: "I was really really amazed that considering this is a major port for the UK to Ireland how a single track road feeds it."
With P&O ferries still not operating after the recent staff sackings, the need for improved transport links between Cairnryan and Northern Ireland are seen to be more important than ever.
"We've invested over a quarter of a billion pounds upgrading the ferries and the roads and I think the roads are just the missing part here," says Paul Grant, the Trade Director from Stena Line. "I think if it's easier and the journeys are faster it can only benefit tourism and our business."
Michael Robinson, the Port Director at Belfast Harbour, described the problems with the A75.
"It's a really slow road, it's dangerous and the improvements needed will make it faster, greener and safer," he said.
What's expected to happen now is that the UK Government will come up with a pot of money to upgrade that road and and will ask the Scottish Government to work with it. The Scottish Government has said it is prepared to discuss a shared vision. So there is some hope tonight that the upgrading of that road is moving a step closer.