The Brexit Secretary was accused by Labour of trying to silence Parliament after sending a letter and document on a so-called “meaningful vote” on the Withdrawal Agreement to a committee of MPs.
MPs will have to vote on any agreement Mrs May brings back from Brussels, with opposition parties and even some of the Prime Minister’s allies warning that they may not back it, which would risk a no-deal Brexit.
Both Remainer and Brexiteer MPs have suggested that the vote legislation could be amended to make changes either keeping the UK closer to the EU or moving it further away than the deal might allow.
But in a memo sent to Procedures Committee chairman Charles Walker last week and published on Wednesday, the Government warned that any amendments “could have the effect - whether deliberately or accidentally - of inhibiting the Government’s legal ability to ratify the Withdrawal Agreement”.
In an accompanying letter, Mr Raab said: “Once the deal is presented to Parliament, the procedure through which it is voted upon must allow for an unequivocal decision, and one which is clear to the British public.
“Anything other than a straightforward approval of the deal will bring with it huge uncertainty for business, consumers and citizens.”
But shadow Brexit Secretary Keir Starmer said: “Labour doesn’t accept that the choice facing Parliament will be between whatever deal Theresa May cobbles together or no deal.
“That is not a meaningful vote and ministers can’t be allowed to silence Parliament.
“MPs must be given the opportunity to scrutinise, consider and, where appropriate, amend any resolution the Government puts forward.”
There were tense scenes in Parliament over the summer as Brexit legislation went through the Commons and Lords, with amendments seeking to give MPs a greater say ahead of the vote.
The Prime Minister saw off several revolts from her own MPs and the Lords with scenes including ill and heavily pregnant MPs being brought into the Commons for tight votes.
Tory Nicky Morgan, a pro-Remain MP involved in some of those attempts, said on Twitter: “This appears to be an attempt by the Executive to frustrate our sovereign Parliament - it is clumsy, it won’t succeed & it shows how hollow ‘taking back control’ was for some people.”
A Government spokeswoman said: “The evidence provided at the request of the Procedure Committee simply sets out the different ways in which you could take amendments during the vote on the final deal.
“It also sets out the issues that could arise if the vote does not lead to a clear outcome that provides legal certainty. We look forward to hearing their views.”