The leader of Plaid Cymru has called for a referendum on Wales' future, after the UK Government again threatened to overrule Welsh Government policies.

On Tuesday, Westminster announced its intention to repeal the Welsh Government's 2017 Trade Union Act, which bans agency staff from being used if public sector workers go on strike.

Calling the move "potentially devolution’s breaking point", Plaid leader Adam Price has urged a strong response from the Welsh Government, suggesting that the question of Wales' future in the United Kingdom should be put to the public in a referendum.

"Westminster wants it to be a relationship where they are in control and our Senedd is subservient - where their Parliament is supreme and ours is subordinate," Mr Price said at First Minister's Questions on Tuesday.

"[They] have shown their contempt not just for workers, not just for Wales, but for our democracy.

“This is not just one more in a long list of power grabs - it’s a turning point.

"It rolls back the rights of citizens, but also it denies those citizens' very right to decide their own future.

“There has to be a political response that will make Westminster sit up and listen. 

"A strongly worded letter from the Welsh Government is not going to work.

"The First Minister’s response to the Westminster power grab is to hope for a Labour success in the next General Election, but what happens if Labour loses the next general election and the one after that?"

First Minister Mark Drakeford implied that such a referendum should only be held if Plaid Cymru - or any other pro-independence party - won a majority in the Senedd.

"I've always argued—and I’ve got into trouble for it from time to time—that if the people of any constituent part of the United Kingdom vote for a referendum on their future, then they should be allowed to hold that referendum," he said.

"I think that that would be the case in Wales as well.

"If a party that stands for that at an election wins a majority of votes in Wales, then of course that referendum should happen.

"But that hasn’t happened here in Wales, and, until it does, I think that the case that the Member makes is fatally weakened."

Westminster's announcement is thought to be a reaction to last week's RMT rail strikes, which saw around 50,000 railway staff - from ticket collectors and cleaners to signallers and maintenance workers - walk out over pay cuts and working conditions.

Teachers, doctors, firefighters and postal workers are just some of those that could go out on strike in the coming weeks and months - again over pay cuts, jobs and working conditions - and bringing in agency staff would damage the ability of these workers to win their disputes.

Here in Wales, that practice is banned for public sector strikes. The UK Government wants to remove that ban - the latest in a series of measures which have contradicted Welsh Government policy approaches and directly limited its lawmaking powers, such as the post-Brexit Internal Markets Act, and the Policing Act.

These ongoing tensions have called into question the future of Wales in the union.

“Plaid Cymru has a very simple answer to this situation, which would remove Westminster’s right to run roughshod over our democracy permanently – not just in the brief interludes of a Labour Government once every twenty years - and that is independence," Adam Price said.

“If Labour is not prepared to back independence now, then surely they can back a consultative referendum on Wales’ constitutional future.

"If it’s framed as Wales versus Westminster then surely it’s a referendum that we can win?”