The Scottish Secretary said he did not think a settlement could be reached over the EU Withdrawal Bill and blamed the Scottish Government for trying to change the constitution.

Government defeated heavily in Lords on '˜meaningful' Brexit vote

Mr Mundell rejected calls from the SNP and Labour for him to stand aside ahead of an emergency debate secured following last week’s turmoil over the lack of debate on devolution provision in the Withdrawal Bill.

SNP Westminster leader Ian Blackford speaks in the House of Commons. Picture: PA Wire

The SNP’s Westminster leader Ian Blackford, who led his MPs out of the Commons chamber in protest last week, called plans to retain 24 powers in devolved areas after Brexit a “smash and grab” and said the row would “haunt the Tories for a generation just as the Poll Tax did”.

Mr Blackford claimed the devolved settlement had been “emasculated by an anti-Scottish Government,” which had used its majority in England to perpetrate a “power-grab” from the Scottish Parliament.

He is calling for legislation to secure the place of the Sewel Convention, which states that UK government may not normally act in devolved areas, in law. The SNP has threatened a “guerilla campaign” in the Commons if the government fails to meet its demands, with plans to hold up votes on crucial Brexit legislation and borrow tactics Charles Stewart Parnell’s 19th century Irish nationalists to frustrate the government’s agenda.

Mr Mundell rejected calls from the SNP and Labour for him to stand aside

Relations between the two governments, and betweeen the Tories and SNP in the Commons, have reached a new low with a UK government source telling The Scotsman that it would no longer be “walking on eggshells” in talks with Edinburgh because “all the eggs are broken”.

“The UK government must now come to the table with emergency legislation, not just more excuses that simply will not wash with the Scottish people,” said Mr Blackford.

“There will be no business as usual until this attack on devolution ends. Scotland will not be silenced, and the SNP will do everything in our power to defend devolution and protect Scotland’s interests.”

Yesterday Mr Mundell told the BBC’s Sunday Politics Scotland programme: “The government set out its position in line with the existing constitutional settlement and at the heart of this… is that the SNP don’t accept the existing constitutional settlement.

“They want to change that settlement, they want to bring about independence, they don’t hide that.

“The core of this dispute is that there are just two different views of how Scotland’s place should be in the future.”

He added: “I don’t think there is a settlement to be had. I’ve always looked to bring forward agreed amendments, amendments that had been agreed with the Scottish Government, but it’s become quite clear throughout this process that it’s not possible to reach that agreement.”

As recently as January, Mr Mundell had said he was “confident we can reach a place where the Scottish Parliament will give legislative consent”.

Labour MP Paul Sweeney repeated calls for Mr Mundell to step down, accusing him of an “abject failure of leadership”.

Shadow Scottish secretary Lesley Laird called for all-party talks to find a solution.

“The people of Scotland deserve nothing less than a devolution settlement that protects the integrity of the UK single market and upholds the powers of the Scottish Parliament,” Ms Laird said.

“This entire process has been marred by Tory chaos and Nationalist mischief making – with neither side putting forward a long-term plan for our country’s future. It is time for Scotland’s two governments to set aside their political differences.”

Liberal Democrat MP Christine Jardine said the two sides had months to reach a deal, adding: “The public would be forgiven for calling a plague on both their houses.” Conservative MP Kirstene Hair said the SNP were relying on “fake claims and hyperbole”.

SNP brands Tories '˜anti-Scottish' as door closes on Brexit deal