The UK Government has acted “without regard” for the devolved nations and continuing to do so will strengthen the case for the break-up of the Union, Mark Drakeford has said.

The Welsh First Minister said the United Kingdom has “never been this fragile”, as his Government prepares to unveil its ‘Reforming Our Union’ plan to reset relations with Westminster.

The 20-point plan argues England, Scotland, Wales and Northern Ireland must be based on a partnership of equals, and calls for the creation of an independent body to oversee how “fair” funding is allocated across the nations.

It also calls for reforming the House of Lords to reflect the make-up of the United Kingdom, giving devolved ministers a say in the UK’s approach to international relations, and the devolution of justice and policing to Wales as had already been done in Scotland and Northern Ireland.

Wales First Minister Mark Drakeford arrives at the Senedd in Cardiff Bay (PA)

Ahead of unveiling the plan in the Senedd on Tuesday, Mr Drakeford said: “Wales’ future is best served by having strong devolution – so decisions about Wales are made in Wales – and by being an equal partner in a strong and revitalised United Kingdom.

“For this to happen, the way the Union works must change. And the need for change is urgent – the Union has never been this fragile. If matters continue in their current vein the case for the break-up of the UK will only increase.”

Mr Drakeford said Westminster often acts in “an aggressively unilateral way, claiming to act on behalf of the whole UK, but without regard for the status of the nations and the democratic mandates of their government”.

“We see muscular unionism, instead of working towards a genuinely constructive and collaborative relationship between the governments of the UK,” he said.

“It’s time for relationships to be reset. The principles and ways of working we have outlined would lead to the strong and durable Union – a union which we believe would deliver the best outcomes for the people of Wales and the wider United Kingdom.”

The plan also suggests the UK Government should agree it will not fund other governments’ responsibilities without their consent, following criticism from Wales and Scotland that the Internal Market Act allows Westminster to allocate money to devolved areas.

The plan was originally published in October 2019, when Mr Drakeford called for a “radical redrawing” of the UK, but has been updated following Brexit as well as May’s parliament elections for Wales and Scotland.

The UK Government described the report as an “irresponsible and unwanted distraction” during the coronavirus pandemic.

A spokesperson said: “People in Wales want to see the UK Government and the devolved Welsh Government working together to defeat the pandemic and focus on our shared recovery.

“Choosing to prioritise constitutional issues in the middle of a pandemic is an irresponsible and unwanted distraction.

“We are strongest when we work together as one United Kingdom, and our full focus must remain on recovering from the challenges the pandemic has created – protecting jobs with furlough payments, ensuring our children can catch up on their missed education and finding jobs for our young people.”

The Welsh Conservative Senedd leader Andrew RT Davies said: “Just weeks after the Senedd election, people across Wales will be left scratching their heads at the fact this is now the priority for the latest Labour administration in Cardiff Bay.

“We’ve been through an incredibly difficult period and what people want to hear from governments and ministers of all stripes is how they’re going to protect jobs, secure new opportunities and deliver a clear plan for Wales’ economic recovery, not constitutional debate and demands for more powers and politicians in the Senedd.”