In a major speech on the future of devolution once the UK leaves the EU, Cabinet Office minister David Lidington will say the UK is “at a crossroads in our history”, with failure to break the deadlock resulting in “a poorer country that is divided at home and a weaker player on the global stage”.

Ministers from the UK, Scottish and Welsh governments are expected to meet for the second time in two weeks seeking agreement on how powers in devolved areas returning from Brussels will be managed, with devolved administrations threatening to trigger a constitutional crisis by refusing consent for essential Brexit legislation.

Yesterday Mr Lidington warned that the SNP’s demand for all 111 powers returning from Brussels to be fully devolved would mean the UK leaves the EU “as a country split and an economy disjointed”.

First Minister Nicola Sturgeon (Photo by Jeff J Mitchell/Getty Images)

He said striking trade deals with the EU and the rest of the world will be impossible if devolved governments refuse to accept that Westminster retains an effective veto over as many as 25 powers currently held by Brussels, in areas including agriculture, fisheries, the environment and public procurement.

But in a sign of deepening division, Scottish ministers said they will let Westminster retain powers that allow the “hard right” to set the agenda for trade deals that could affect food standards, environmental protections and the health service in Scotland.

“We face a choice: A choice that represents the difference between a prosperous, secure nation that is united at home and stronger abroad, and a poorer country that is divided at home and a weaker player on the global stage,” Mr Lidington is expected to say in his address at the Airbus factory in North Wales.

“Our aim should be nothing less than to see our entire country coming together and having their voices heard.”

Amendments proposed by the UK Government at a meeting of the Joint Ministerial Committee last week “would mean a very big change to the EU Withdrawal Bill”, Mr Lidington will insist, saying the offer “doesn’t just respect the devolution settlements, but strengthens and enhances them”.

However, Mr Lidington will insist that some of the powers returning from Brussels “are clearly related to the UK as a whole and will need to continue to apply in the same way across all four nations”.

Pledging to protect the “common market” of the UK, Mr Lidington will say: “That market is one of the fundamental expressions of the constitutional integrity that underpins our existence as a union.”

In a warning to the SNP not to try and use Brexit to argue for independence, Mr Lidington will say: “We are all more prosperous and more secure when we all work together for our common good as one United Kingdom.

“Leaving the EU presents many challenges for our centuries-old union story - and opportunities too.

“Some want to use it as an excuse to loosen these ties that bind us together – even sever them completely.

“Such an outcome would leave every one of our four nations both weaker and poorer.”

The UK Government has until mid-March to table amendments to the Withdrawal Bill, which is currently before the House of Lords, and must secure an agreement with the devolved administrations by then or risk Holyrood and Cardiff Bay rejecting legislative consent.

The Scottish Government’s Brexit minister Michael Russell said Mr Lidington’s comments meant “the cat is out of the bag”.

“The current discussions between the Scottish and UK Governments centre only on powers which are already devolved,” Mr Russell said.

“The Tories have now made it crystal clear they want to take control of some of these devolved powers as part of their plan for a disastrous hard Brexit outside the EU Single Market and Customs Union.

“This raises some very troubling questions for issues such as food standards and environmental protection.

“And if, for example, a proposed future trade deal involved healthcare, could Scotland be forced down the same route as England and made to open up our health service to private providers?”

Mr Russell added: “We have made clear that we are not opposed in principle to common frameworks where a case can be made, but these must be agreed on the basis of genuine mutual consent.

“That has been our approach throughout the negotiations and will continue to be so, no matter how hard the UK Government tries to undermine the devolution settlement to please its hard-right supporters in the House of Commons.”

'˜SNP's demands put Brexit trade and future of UK at risk'