Boris Johnson is in danger of “sleepwalking” into the break-up of the United Kingdom, Welsh First Minister Mark Drakeford has warned,

Mr Drakeford said the Prime Minister’s “instinctive” hostility to the devolution settlement was fuelling support for independence in Wales.

Giving evidence to the House of Lords Constitution Committee, he said the Welsh Government was a “rather vanishing creature” in that it still believed in the UK.

“The state of the Union is under the greatest pressure it has ever been in my political lifetime,” he said.

“In the current UK Government we face for the first time in the history of devolution a Government that is instinctively hostile to devolution.

“The Prime Minister told Conservative backbenchers that devolution was the greatest mistake of the Blair government.

“The actions of his administration bear the hallmark of that. The confrontational approach, the approach of muscular Unionism, aggressively unilateral in the way it goes about things.

“We are sleepwalking, if we are not careful, into the end of the Union as we know it.”

Mr Drakeford said the actions of the Government were making it increasingly difficult for him to make the case for the Union in Wales.

“Every single day they create new tensions between us and go on persuading a growing sector of opinion in Wales that Wales will be better off outside the Union,” he said.

“We have example after example of where powers are devolved to Wales and where the approach of the UK Government is to cut in, spend money themselves in those devolved areas, undercutting devolution.

“It stokes political tensions and gives ammunition to those people who have come to the conclusion that the Union is over and we would be better off outside it.

“It is a matter of huge regret to me that I have to roll the stone even further up the hill because the UK actively undermines the case for the Union rather than strengthens it.”

Darren Millar, Welsh Conservative shadow minister for the constitution, accused the First Minister of “flirting with a divisive and hostile nationalism”.

“The people of Wales want him to focus on our recovery from the pandemic, not constitutional change,” he said.

“Labour’s priority should be protecting jobs, tackling unacceptably long waiting lists and improving our education system in Wales – not stoking fear about the future of the United Kingdom.”