However, many would only support the Conservative government if they feared Britain would be on the brink of a Brexit without a deal. Only five Labor MPs supported the deal: John Mann, Rosie Cooper, Kevin Barron, Jim Fitzpatrick and Caroline Flint. Two others, Dennis Skinner and Ronnie Campbell, abstained. Some of those who supported the government will likely face a counter-reaction from grassroots activists, with the threat of impeachment. During the Brexit negotiation process, Grieve made a number of changes to the government`s plans to leave the EU. The first was to give Parliament a « reasonable vote » on the Brexit deal – that is, to impose a request from Parliament to approve the Brexit deal, which would have a binding effect on the government. In December 2017, he tabled an amendment (Amendment 7) to the European Union Withdrawal Act (withdrawal) that requires that any Brexit deal be implemented by law and not by government decision. The amendment was rejected by the government but passed by Parliament.  Another amendment, tabled on 12 June 2018 (Amendment 19) and again on 20 June, was intended to strengthen the binding effect of the meaningful vote by requiring the government to comply with the instructions of a parliamentary motion if Parliament does not approve the withdrawal agreement tabled by the government.
Grieve threatened to rebel, but ultimately voted with the government against the amendment following verbal assurances from Prime Minister Theresa May which were presented as a compromise;  The result was summed up by the Guardian as follows: « Technically, MPs can still vote on the final agreement – or no deal – but if it is not a vote of confidence, the government can ignore it. »  Grieve`s Third Amendment, in December 2018, would mean that Parliament would replace the government to decide the outcome of Brexit, after the government voted against the government`s proposed deal with the EU.  At the end of November 2018, May presented to the House of Commons a draft agreement on future relations with Europe after concluding 17 months of negotiations with the EU.  As a result, the first use of the judicious vote was scheduled for December 11, 2018.  On the morning of the vote on 12 June 2018, the government rejected Grieve`s alternative amendment.