MPs vote to give Parliament power to take control of Brexit if Commons votes down Theresa May's deal

Former attorney general Dominic Grieve leads successful cross-party bid to ensure Commons can tell ministers how to respond if proposed agreement is rejected

Theresa May has been dealt a major blow after MPs voted to allow Parliament to seize control of Brexit if the House of Commons votes down the prime minister's deal.

MPs backed a motion tabled by Dominic Grieve, the former attorney general, to allow the Commons to amend the government's plan for how to proceed if, as expected, Ms May's proposed agreement is voted down on 11 December.

Mr Grieve's amendment passed by 321 votes to 299 after a number of Tory MPs voted against the government.

The move means a no-deal Brexit is now highly unlikely, given a clear majority of MPs are opposed to such an outcome. Even if the government decides to pursue no-deal, MPs would now have the power to oppose it. While such a vote would not be legally binding, it would be almost impossible for ministers to ignore.

Mr Grieve's amendment was backed by MPs from across the Commons, including 26 Conservative rebels.

In addition to pro-EU Tories who have previously voted against the government, it also received support from MPs who have traditionally been loyal to Ms May.

Supporters included former cabinet ministers Sir Oliver Letwin, Sir Michael Fallon and Nicky Morgan, as well as Ms May's former deputy, Damian Green.

It was also backed by Nick Boles, who is garnering support among MPs for a "Norway for now" option that would see the UK remain in the European Economic Area (EEA) and customs union until a further arrangement was agreed with the EU.

Many of the Tory MPs who backed the amendment did so despite having already said they will vote for Ms May's deal.

Mr Grieve pushed the motion to a vote shortly before Ms May opened five days of debate on her proposed withdrawal agreement.

The amendment will fundamentally alter the sequence of events that will follow if the prime minister's deal is rejected by MPs.

Under the terms of the EU Withdrawal Act, the government must publish a statement within 21 days of the deal being voted down outlining how it plans to proceed, and MPs must be given a vote on this within a week.

The vote, though, would only be on a "neutral motion" simply saying the Commons had considered the matter. Crucially, MPs would not be able to amend the motion in order to express a view on what action ministers should take.

Mr Grieve's amendment changes that. It says parliamentary rules stating that neutral motions cannot be amended should not be applied to government motions on Brexit.

That means MPs will be able to order ministers to change tack, for example by extending Article 50, reopening negotiations with the EU or calling another referendum.

A similar motion has been tabled by the chairs of several parliamentary select committees, including Brexit committee chair Hilary Benn. However, their amendment explicitly rejects Ms May's deal, meaning it is unlikely to be supported by Tory MPs who are backing the prime minister's plan but want Parliament to be given greater control if the Commons rejects it.

Speaking in favour of his motion, Mr Grieve told the Commons: "The reality remains that we have an unsatisfactory procedure to resolve differences of opinion in this House if we come to a point where the government does not succeed on its motion. The opportunity exists this afternoon to cure that anomaly.

"It is contrary to all sensible practice, and I have to say slightly disrespectful of the role of this House, that we should end up with a situation in which we have unamendable motions for consideration at a time when Parliament ought to be fully focused on trying to find means of resolving outstanding issues."

He said his motion would ensure that "whatever the outcome next week, we have a means of continuing the debate thereafter if we need to".

Speaking for the government, Andrea Leadsom, leader of the Commons, told MPs it was "not the time to pre-empt whether or not further motions" are likely as a result of Ms May's proposed deal being rejected.

The amendment secured the guarantees Mr Grieve general initially tried to extract from ministers during debates on the EU Withdrawal Act in June.

Having tried to ensure MPs would be able to amend the government's motion in the event the Brexit deal is rejected, the former attorney general eventually backed down after claiming he had received assurances that ministers would respect the sovereignty of Parliament.

It comes as a senior adviser to the European Court of Justice said that the British Parliament could unilaterally revoke Article 50, thereby halting the Brexit process.

Launching a People's Vote report outlining how Parliament could block a no-deal Brexit, Mr Grieve said: “All the evidence I’ve picked up is that the EU would give us a reasonable period of time to hold a referendum if we wish to do so.

“If Parliament expresses a view that it wishes to have a People’s Vote then unless the government has taken complete leave of its senses, it is possible for us to put in place the necessary procedure to hold such a referendum. And, more over, to make the necessary changes to the EU Withdrawal Act very simply to make sure that we don’t crash out on 29 March.”