Tory Brexit hardliners have issued a fresh warning to Boris Johnson ahead of his meeting with EU leaders in Brussels.
Sir Bill Cash, chairman of the European Scrutiny Committee, told the prime minister that they will be “watching” with “great diligence” over what he proposes and they hope their confidence in him will be justified.
The MP for Stone also claimed the country was at its “most important moment” in its history in the last 250 years, as talks between the UK and EU over future arrangements beyond December 31 come to a head.
His remarks came as MPs debated the resolutions related to the Taxation (Post-Transition Period) Bill with such motions needed to authorise the creation, extension or increase of taxes or other charges.
The Bill has yet to be published, prompting concern among MPs but treasury minister Jesse Norman insisted it will play an important part in post-Brexit preparations.
Ahead of the debate, Cabinet Office minister Michael Gove said controversial powers enabling ministers to breach international law over the Withdrawal Agreement would be dropped from this Bill and the UK Internal Market Bill.
The announcement followed confirmation that the UK and EU have reached an agreement on the implementation of the divorce deal, resolving issues relating primarily to the Northern Ireland Protocol.
Sir Bill said: “All I can say, however, is we will be watching all these matters with great diligence and with a constructive approach because I trust when we’ve been through the full proceedings on this Bill and finalising the Internal Market Bill, we will hope and trust that the confidence is entirely justified and there’ll be no impairment of our sovereignty of the United Kingdom – which is what this is all about.
“I’ll simply conclude by saying this: not since 1688 have we been faced with a situation of such historic importance, other than when we went into the European Union under the false pretences of a white paper which turned out to be unfortunately misleading the British people.”
He added: “This is the most important moment in our history in terms of the last 250 years whereby we have regained the sovereignty that was embedded in the arrangements after 1688/89.”
Sir Bill went on: “This is our sovereignty and we have absolute total determination, as I understand so does the prime minister, to maintain that.
“It’s about democracy, it’s about freedom, it’s what Churchill was proud of, it’s what Margaret Thatcher was proud of, it’s what we’re proud of – and I simply make this final point, we will maintain our sovereignty at any price.”
DUP MP Sammy Wilson described the Withdrawal Agreement as “poison”, and said the government should not remove powers to override international law until it is sure the remaining issues have been “properly dealt with”.