The bill engages the Sewel Convention and therefore requires the consent of Holyrood.

Constitution Secretary Michael Russell said: “It beggars belief that the UK government is asking the Scottish government to recommend consent to the Internal Market Bill. This is not a genuine partnership of equals and we couldn’t recommend consent to a bill that undermines devolution and the Scottish Parliament, and which, by the UK government’s own admission, is going to break international law.

“This is a shabby blueprint that will open the door to bad trade deals and unleashes an assault on devolution the like we have not experienced since the Scottish Parliament was established. We cannot, and will not, allow that to happen.

“It will open the door to a race to the bottom on food standards, environmental standards and will endanger key public health policies such as minimum unit pricing. It will also deliver a hammer blow to the Scottish economy by making it harder for the UK government to conclude Free Trade agreements if other countries think the UK won’t meet its obligations.

“As each day passes, it becomes clearer that the people of Scotland deserve the right to choose a better direction, to determine their own future. That is why, before the end of this parliament, we will set out the terms of a future independence referendum clearly and unambiguously to the people of Scotland, in a draft referendum bill.”

Scottish Greens co-leader Patrick Harvie said: “This bill is every bit as bad as we feared. It places a veto in the hands of Boris Johnson over any devolved decisions which gets in the way of his free market extremism. Even his own ministers admit it is unlawful. It must be stopped.

“It threatens our environmental, food and farming standards. It threatens Scotland’s decisions to ban fracking or prevent new nuclear power stations. It could be applied to our bold public health measures such as minimum unit pricing, and it certainly could allow further private sector involvement in our NHS.”