The Lib Dems have accused the UK Government of refusing to rule out adding international law-breaking legislation that could undermine devolution.
North East Fife MP Wendy Chamberlain raised her concerns following a question in the House of Commons, answered by Paymaster General Penny Mordaunt MP.
Ms Chamberlain asked about clauses that could give the government a “pass” on breaking international law, should the UK fail to agree an exit deal with the EU before January 1.
The Lib Dem spokesperson on the constitution’s comments followed SNP concerns of an undermining of Holyrood earlier this week.
MSPs voted in October not to consent to the UK Government’s legislation to set up an “internal market” after Brexit.
The Bill will give the UK Government the power to spend in devolved areas, such as health, housing and education.
Ms Chamberlain said: “I’m disappointed the government refuses to rule out reintroducing law-breaking legislation.
“Instead of working with partners and ensuring the smooth running of the UK internal market, they fundamentally undermine it, sowing tensions between Westminster and the devolved administrations.
“This Conservative government, led by Boris Johnson, continues to be the greatest threat to the United Kingdom as they fan the flames of nationalism at home and abroad and undermine our standing in the world.”
Question asked in House of Commons
Ms Chamberlain asked: “If there is a no-deal outcome this weekend, do the government have any plans to bring forward new measures that break international law, either in the Taxation (Post-transition Period) Bill, which was introduced this week, or as part of any unknown business?”
Ms Mordaunt responded: “The Honourable Lady will know the reasons why those clauses were in the UKIM Bill.
“We will not compromise on the integrity of the United Kingdom. The fact that the Prime Minister made that offer shows that we are doing everything we can to be creative and try to ensure we get a preferable outcome.
“As I say, the prime minister has resolved that he will not move on those red lines.”