The SNP leadership has signalled that last-ditch talks to resolve the cross-border deadlock over Brexit are doomed.

Ian Blackford, the Nationalist leader at Westminster, said it was likely the constitutional battle over devolution of powers after Brexit would transfer to the UK Supreme Court.

The Scottish and UK governments are locked in dispute over the EU Withdrawal Bill, which ministers north of the Border have called a "power grab".

Hours before the latest Joint Ministerial Committee[JMC] meeting in Whitehall had even started, Ian Blackford, the Nationalist leader at Westminster, effectively conceded there would be no breakthrough before the deadline of May 16, when the bill's final reading in the House of Lords is expected to take place.

Mark Smith: Sturgeon has a point on Brexit deal but she’ll pay a high price for being right

After a plea from SNP colleague Patrick Grady to pause the legislation until Holyrood is able to give consent was brushed aside by the UK Government, the Westminster leader was asked if this did not smack of desperation by the Nationalists.



“No, not at all,” declared Mr Blackford. “The Government in Edinburgh wants to reach agreement but it seems we are not going to reach one. That appears to be where we are; we are right at the wire.”



He went on: “It’s wholly regrettable and it’s putting it mildly that we are now in a situation where in effect the two governments are going to have to seek to resolve this through the Supreme Court.

"It’s absolutely unprecedented that we are in this situation and it will be up to the court to try to navigate its way through this if the governments can’t reach agreement.”

READ MORE: Peers inflict further damage on Theresa May’s Brexit plans

Stressing how the Scottish Government believed it had a “very robust case” to put before the court in arguing that Holyrood’s Continuity Bill was competent and should become law, the Highland MP declared: “We have an obligation to defend the devolution settlement. There was no other alternative to that.



“The fact the UK Government is prepared in effect to ignore what is there in statute from the 1998 Scotland Act is absolutely scandalous.”



The JMC had been originally planned to last 90 minutes but lasted just an hour.



Michael Russell, the Scottish Government’s Brexit Minister, who left without facing questions from the press, said in a later statement that the Scottish Government was still working towards getting an agreement but “not at any price”.

READ MORE: Theresa May promises 'robust' response to Lords defeats

He said the UK Government’s “power-grab” proposal would mean that for the first time the powers of the Scottish Parliament could be changed without the approval of MSPs.



David Mundell emerged from the JMC saying it was still possible to reach a deal and pointed out how the Supreme Court process was separate from the discussions around Clause 11 of the Withdrawal Bill.



“We are positive about continuing a dialogue...so we will take it up to the wire,” declared the Scottish Secretary.

He said Scottish voters were “sick and tired of constitutional rows” and simply wanted both governments to work to agree common frameworks.



He described the disagreement between the two governments as a “head of a pin constitutional argument”.



On Thursday, he is expected to get a rough ride at the Scottish Parliament when he appears before its Finance and Constitution Committee.



Once the Brexit bill completes its Report Stage next week and before its Third Reading on May 16, it will go to Holyrood for MSPs to decide, or not, to give their consent. Given the SNP Government’s stance, rejection appears certain.



Indeed, both governments are already talking to the Supreme Court about dates for the hearing on the Continuity Bill.

This could take place in the next fortnight or so.