DUP MP Sammy Wilson said it was “fundamental” that Northern Ireland was not separated legally from the rest of the UK

Mr Wilson said: “If the issue of being part of the single market rules and single market laws is removed from Northern Ireland, then there’s no need for the European Court of Justice.”

Asked if that is what he is calling for, he said: “It would ensure that Brexit actually applied to Northern Ireland, it would ensure that the UK Government had sovereignty over this part of the United Kingdom and that Northern Ireland was not separated legally from the rest of the United Kingdom as a result of the protocol.

“That’s fundamental. Indeed, that is not something that we have been asking for alone, the Government itself in its command paper last autumn, and in the Protocol Bill which is now stalled in the House of Lords, was demanding that as well and saying that if the EU did not come to that point in negotiations, that they would act unilaterally to ensure that that happened.

“So, we will be saying to the Prime Minister … this is what you have promised in your own Bill, this is what you have said needs to be done in your own command paper, and this is something which our seven tests will make a judgment on as to whether or not it’s been achieved.”