NICOLA Sturgeon’s approach to post-Brexit devolution is "back to front" and would cause gridlock and uncertainty to the UK’s internal market, Green Damian has warned.

However, as Theresa May’s deputy prepared to meet John Swinney, the Deputy First Minister, for more bilateral talks in London today, he expressed “optimism” that the UK and Scottish Governments could find a way forward and avoid a constitutional crisis.

The First Minister has made clear that, as things stand, she could not endorse Holyrood giving its consent to the UK Government's flagship EU Withdrawal Bill, claiming it was a "naked power-grab" by Whitehall.

Last week, David Mundell expressed frustration at what one UK Government insider described as a “confected constitutional grievance” from Edinburgh and called on Ms Sturgeon to “stop playing games and get serious”.

This sentiment was echoed by Mr Green, who said: “I believe There are grounds for optimism and that we can make progress at the meeting.

“Both Governments agree we need to get ready for Brexit. We both agree a UK approach will be required in certain areas. And there is no doubt that Holyrood will end up with more decision-making powers at the end of this process. It is now time to get serious,” declared the First Secretary of State.

Referring to the Prime Minister’s speech in Florence last week, he insisted that the plan to “strengthen the role” of the UK and Scottish Parliaments in deciding our laws would benefit Britain greatly.

Mr Green went on: “The UK Government’s priority is providing continuity and certainty, so not to damage our hugely beneficial internal market and not to burden businesses with extra barriers to trade. We know that this is what people and businesses in Scotland want.

“EU law intersects with devolved competence at Holyrood in 111 policy areas. We need to start working through this list of areas with the Scottish Government in a serious manner to determine what areas will require a UK approach and where different practices will be acceptable.

“The Scottish Government position is that we should devolve absolutely everything to them and only then start to talk about how we rebuild the internal UK market.

“But this logic is back to front. We are not going to take risks with the UK market; risks that could cause real hardship to businesses and consumers.

“It makes no sense to potentially dismantle or disrupt large parts of our UK internal market and then hold talks on how we might be able to rebuild it; that is sure to result in gridlock and uncertainty,” he added.