THE court challenge to the UK Government’s “power grab” act is set to be heard at the end of March after Welsh ministers launched formal proceedings over the legislation.

A request has now been lodged for a judicial review of the UK Internal Market Act, in a case which is being backed by the Scottish Government.

Welsh Counsel General Jeremy Miles said there was likely to be more talks with other devolved governments once the application for judicial review was heard.

Constitution Secretary Michael Russell has previously said that also taking steps within Scotland had “not been ruled out”.

In statement last week, the Welsh Government outlined the grounds for the challenge including that the act “implicitly repeals” parts of devolution law in a way that “diminishes” the Welsh Parliament’s legislative competence.

It stated the legislation also handed powers to UK ministers which could be used to “cut down” the devolution settlement.

In a speech to Cardiff University’s Wales Governance Centre, Miles said Boris Johnson’s government had used its Commons majority to push through a bill which represents a “fundamental challenge” to the Senedd, the Scottish Parliament and the Northern Ireland Assembly.

He said the UK Government had also claimed the bill increased the powers of the devolved institutions.

But he added: “That is a claim which hasn’t been backed by any independent commentators or academics and is demonstrably not true.”

Miles described the UK Internal Market Act as “effectively a constitutional overhaul masquerading as market regulation”.

He said it was not common to challenge acts of parliament, but Welsh ministers believe they have a “good set of arguments”.

“In the passage of the bill through Parliament, and in correspondence with us as ministers, there are many, many examples of UK Government ministers saying in the two chambers the intention in the bill is not to cut back the devolution settlement,” he added.

“What these proceedings are effectively about is to make that political intention a matter of law. So in that sense, you would hope the UK Government would agree with that.”

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Scotland’s Lord Advocate has been named as an “interested party” in the submission to the court, along with the Attorney General for Northern Ireland.

Miles said this was a “technical” reference rather than indicating they were actual parties to the case, but added the Scottish Government had been very supportive.

“Certainly in the past in litigation and in other contexts, we have worked as three devolved governments, three devolved law officers, in legal challenges,” he said.

“The reality of what will happen is we will see what happens to the application for leave for judicial review and if, as I hope and expect, it is granted, I think at that point there will be a more practical discussion about other governments and so on.”

Kenneth Armstrong, professor of European law at the University of Cambridge, said the Welsh Government was seeking an advisory declaration from the court.

He said, if successful, this would “simply clarify what the law is” and the UK Internal Market Act would remain in place.

But he added: “A broad function of the litigation might be simply to ensure legal certainty so that everyone knows the limits of what effects the UK Internal Market Act can have on devolution.

“A narrower, more political function could be to demonstrate that the Welsh and Scottish governments are defending devolution.”

Tom Mullen, professor of law at Glasgow University, said the Welsh Government’s arguments would be likely to apply equally to Scottish devolution.

He added: “The UK Government’s position – as set out in the pre-action letter – is that the declarations the Welsh Government is asking for are abstract and/or hypothetical, and the court should not decide these issues now.

“Rather, it should await some future attempt by the Senedd to legislate on goods and services and only decide then.

“I can’t be certain but I think that there is a reasonable prospect that the court will decide the main issues.”

The UK Government said last week it was “disappointed” at the Welsh Government’s stance, and the “vital” UK Internal Market Act would protect jobs, and businesses.