DAVID Mundell and fellow Scottish ministers will be quizzed today about whether or not the transition of powers going to Westminster from Brussels post Brexit could be time-limited.

The issue of transference has been a bone of contention, which could yet result in a constitutional crisis between London and Edinburgh.

Nicola Sturgeon has made clear she regards the UK Government’s flagship EU Withdrawal Bill as nothing more than a “power-grab” by Westminster as scores of powers she believes should go straight to Holyrood will be taken over, in the first instance at least, by Whitehall.

The First Minister insists that until the legislation is changed she could not recommend Holyrood gives its approval to it through a Legislative Consent Motion[LCM].

But the UK Government stresses how more powers will be sent to the Scottish Parliament but it firstly wants to ensure that no further devolution would in any way undermine the country’s internal market.

One issue that will be raised with the Scottish Secretary and his colleagues, Lord Duncan, the Scotland Office minister, and Lord Keen, the Advocate General, when they are cross-examined by MPs on the Commons Scottish Affairs Committee this afternoon is whether or not it would be appropriate to introduce a two-year “sunset clause,” so that after this time any new powers transferred from Brussels to Westminster would go straight to Holyrood.

Despite Ms Sturgeon’s opposition to the bill, the UK Government is confident that MSPs will in the end give their consent to it.

During the Article 50 court case, Lord Keen famously made clear an LCM was merely a political convention, which the UK Government did not constitutionally have to abide by.

However, politically, it would be a very dangerous path for Theresa May and her colleagues to go down.