The Government is scrambling to avoid a defeat on key Brexit legislation just hours before the Prime Minister travels to an EU summit on Thursday.
The EU Withdrawal Bill will return to the House of Commons on Tuesday and Wednesday, before which Number 10 announced it was accepting a cross-party amendment on so-called Henry VIII powers.
A “sifting” committee will now scrutinise those executive powers required to correct the UK’s post-Brexit statute book.
But it is amendment seven, calling for a “meaningful vote” on the Brexit deal, that is causing the Government the most trouble.
Tabled by senior Tory backbencher Dominic Grieve, and publicly signed by 10 Conservative MPs, it is set to be put to a vote on Wednesday night.
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Ministers have been consulting with Mr Grieve, a former attorney general, as to how to address his concerns.
One Tory MP, recently accused of being a Brexit “mutineer”, said: “Unless the Government accepts it or gives some cast iron guarantee in effect to replicate it – we will push it to a vote.”
The Government conceded the broad principle of putting the UK’s exit deal into law in the Commons last month.
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The Withdrawal Agreement Implementation Bill (WAIB) will incorporate the finalised financial settlement, the citizens’ rights deal, Irish border compromise and transition arrangements into British legislation.
But Mr Grieve has refused to withdraw his amendment, as it guarantees the WAIB would have to be passed as a pre-requisite for the Prime Minister signing off on the Brexit deal.
This would accord the UK Parliament the same sanctioning power as the European Parliament.
Potential Tory rebels have also been promised the issue will be dealt with in the report stage of the EU Withdrawal Bill, due in the New Year.
But the group of MPs feels that promises made to them during the passage of the Article 50 Bill were not kept.
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Sky News also understands that one provision of the Government’s WAIB could effectively temporarily reapply the provisions of the 1972 European Communities Act for a transition period.
Therefore it would unrepeal its repeal in the EU Withdrawal Bill.
This would allow some temporary continuance of EU law and jurisdiction during an implementation phase of “around two years”, as provisionally agreed by the Prime Minister last week.
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A significant number of Tory MPs are also unimpressed with the Government’s own “exit date” amendment, and have told party whips that they do not back the largely symbolic measure to write the Brexit date of 29 March, 2019, into law.
So far, however, the Government has defeated all amendments to the EU Withdrawal Bill, with help from its Brexit-backing DUP partners.
Ahead of the bill’s return to Parliament on Tuesday, First Secretary of State Damian Green will host ministers from the devolved administrations at a meeting of the Joint Ministerial Council.
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Brexit Secretary David Davis will also be present for the meeting with Scottish and Welsh Governments and a representative of Northern Ireland’s civil service.
Legislative consent from these administrations will be required for some aspects of Brexit legislation.