The Scottish and Welsh first ministers have clashed over the idea of a separate Brexit deal for Scotland as leaders from across the UK met at a summit of the British-Irish Council.
Nicola Sturgeon made it clear at the summit in south Wales that she wanted Scotland to continue to be part of the single market even if the rest of the UK leaves it.
But Carwyn Jones, the Welsh first minister, argued that such a move could not work and would lead to border posts being set up between England and Scotland.
Jones, Sturgeon and Northern Ireland’s deputy first minister, Martin McGuinness, were united in the view that Theresa May ought to have attended the summit – the first held since she became prime minister.
During an extra summit called in the summer in the wake of the EU referendum, the leaders of the devolved nations said they would work together to make sure they were not “done over” by Westminster during the Brexit negotiations.
But on Friday, at the first regular summit since the referendum, differences in approach were exposed. Speaking at a press conference after the summit, Sturgeon said the prospect of a “hard” Brexit with the UK leaving the single market was a real possibility.
She said: “We are looking at … how could we best protect our own interest, protect our place in the single market, even if the UK decides to leave.
“Of course that would be challenging, there would be a number of practical barriers that we would have to overcome and the work we are doing right now is to explore how those barriers could be overcome.”
Speaking on BBC Radio Scotland, Jones said: “I can’t see how it would work.” He said separate market access arrangements for Scotland would mean customs posts at the border. “There is no other way to deal with that,” he said.
Jones said the election of Donald Trump made it even more crucial that the UK continued to have free access to European markets.
He said: “This is a changing world and these are tumultuous times. But our focus on retaining full and unfettered access to the single market is unwavering.”
The Irish prime minister, Enda Kenny, told the summit the government in Dublin had no intention of pressing Britain for a border poll that would determine the constitutional position of Northern Ireland. Kenny said there was “enough on our plates with Brexit” without demands for a plebiscite on Irish unity.
In Northern Ireland, 56% of people voted to remain within the European Union in the referendum and nationalist politicians, including McGuinness, said there should be a border poll on the region’s continued existence within the UK.
However, successive opinion polls including one taken after the Brexit vote show a majority within Northern Ireland still prefer to remain within the UK.
In his speech at the summit Kenny compared the Northern Ireland economy to the state-dominated former East Germany, given the province’s heavy reliance on subsidies from the UK Treasury. His reference to East Germany raises the enormous costs Dublin would have to take on to absorb Northern Ireland into a new unitary state.
Kenny also made it clear that he believed Brexit would take longer than two years. He told Sky News that leaving the EU would throw up “more detailed and unforeseen issues than people might have imagined”.
“I would expect to see the ‘divorce’, as it is called, take place but that there be a transition period and then a new relationship founded between the UK and the European Union. I think it will be impossible to do all of the negotiations inside the contemplated two-year period,” he said.
“That’s why I think there is a growing feeling in Europe that there should be a transition period and that might well be longer than those two years. I think it will be.”
Kenny also held a bilateral meeting with Sturgeon before her trip to Dublin on Monday, during which she will become the first serving head of government to address the Seanad, the upper house of the Irish parliament.
Sturgeon said Scotland and Ireland “shared history and a long tradition of co-operation on a range of issues”. She added: “In the post-Brexit landscape, it has become even more important that we work together to protect our shared interests.”
Although the prime minister did not attend the summit, four UK government ministers were present. One of them, the Northern Ireland secretary, James Brokenshire, said: “The prime minister strongly supports the British-Irish Council. That’s why you had two cabinet ministers and two other ministers here today strongly representing the UK government’s perspective.”