The Conservative government has “buried the idea of the UK as a partnership of equal nations” after its controversial Internal Market Bill cleared its final Commons hurdle, the SNP said.
MPs voted 340 to 256, majority 84, in favour of the post-Brexit legislation, despite ministers previously admitting it breaks international law by reneging on the EU withdrawal treaty.
The UK Government argues such powers are needed to protect the relationship between Great Britain and Northern Ireland, amid concerns in Westminster that Brussels could seek to disrupt food goods travelling across the Irish sea.
The Scottish Government has also repeatedly raised the alarm about the Bill’s implications for devolution, saying it is an “abomination” that effectively steals powers from Holyrood.
It will formally ask MSPs in the Scottish Parliament to withhold consent to the Bill next month, although in practice this will not stop it from becoming law.
UK ministers claim Scotland will get more than 100 new powers back from Brussels when the Brexit transition period ends.
But they also say they will set things like environmental and food standards – which are devolved – at a UK level, meaning Scotland would have to accept goods and services from the rest of the UK even if they did not meet standards enshrined in Holyrood legislation.
SNP MPs opposed the Bill at its third reading on Tuesday night.
The party’s Westminster leader Ian Blackford said: “By undermining devolution and blatantly ignoring the wishes of the people of Scotland the Tories are burying the idea of the UK as a partnership of equal nations.
“The Tories have launched the biggest power grab in the history of devolution and – backed by Douglas Ross and his Scottish Tory colleagues – are now one step closer to taking a wrecking ball to the Scottish Parliament.
“The Bill will not only rob the devolved governments of powers over devolved matters and hoard them in Westminster, it will also signal a race to the bottom in food and environmental standards.
“The character of this Tory government is crystal clear – it is consistent in its contempt.
“It has shown complete contempt for the devolved parliaments and it has shown contempt for international law.”
He added: “Scotland now faces key spending powers being stripped away, high standards being watered down, and the threat of low-quality produce – such as chlorinated chicken and hormone-injected beef – flooding our supermarkets, and all imposed by a Tory government we didn’t vote for.”
But Scottish Conservative leader Douglas Ross has repeatedly denied the legislation constitutes any kind of power grab, and insisted the legislation is needed to protect jobs in Scotland.
Former prime minister Theresa May and two ex-attorney generals, Geoffrey Cox and Jeremy Wright, were among 21 Conservatives who did not vote for the UK Internal Market Bill at its third reading.
To stave off a wider Tory backbench rebellion, the government was forced to compromise earlier in the Bill’s passage to give MPs a vote before ministers can use the powers which would breach the withdrawal agreement brokered with Brussels last year.
Meanwhile, the EU has set a deadline of Wednesday for the UK to withdraw the Northern Ireland provisions from the legislation.
At talks in Brussels on Monday, the Cabinet Office minister Michael Gove made clear the government was not prepared to back down despite a renewed threat by the EU of legal action.
Despite the row, the two sides are continuing talks on a free trade deal in the Belgian capital between the EU’s Michel Barnier and the UK’s chief negotiator Lord Frost.
Both sides have acknowledged that time is running out, and that agreement needs to be in place by mid-October.
The Prime Minister has said that he is prepared to walk away from the negotiating table if it cannot be settled by the EU summit on October 15.