Motion to force government to give parliament more say on Brexit gets cross-party backing ahead of crunch vote

Cross-party peers set to unite to inflict latest defeat on government as EU Withdrawal Bill reaches final stages

Senior members of the House of Lords have given their backing to a motion that could force Theresa May to let parliament set the terms of Brexit.

In a joint article for The Independent, Labour, Liberal Democrat and crossbencher peers said the amendment, tabled by the Conservatives’ Viscount Hailsham, enshrined the idea that “the future of our country should be determined by parliament”.

Their intervention comes ahead of a crunch vote on the issue on Monday. Defeat for the government could see ministers forced to allow MPs and peers to dictate the terms of the exit deal Britain negotiates with the EU.

Lord Hailsham’s amendment seeks to give MPs and peers a meaningful say over what should happen if the government fails to agree a deal with Brussels, or the deal it reaches is rejected by parliament.

It would force Ms May to let parliament bind ministers’ hands if the terms of the final deal have not been approved by the House of Commons, and discussed by the House of Lords, by the end of January 2019. The same conditions would apply if the withdrawal agreement with the EU is not finalised by 28 February 2019 – a month before Britain is due to leave the bloc.

Ministers have promised to give both houses of parliament a “meaningful vote” on the deal but have not said whether this will be legally binding. They have also insisted that, should MPs vote down the motion, Britain would crash out of the EU without a deal, rather than return to the negotiating table.

However, last week David Davis, the Brexit secretary, admitted there is nothing to stop MPs tabling amendments to the motion, meaning parliament would be able to tell ministers to offer a second referendum on the final deal, or return to Brussels and negotiate different terms.

Lord Hailsham’s amendment would ensure there is enough time for this to happen by forcing the government to hold the “meaningful vote” by 30 November at the latest – four months before Britain is due to leave the EU.

The row over what should happen if parliament does not approve the final Brexit deal is likely to result in another House of Lords defeat for the government on its flagship EU Withdrawal Bill.

Peers have already defeated the government six times, with the vote on the Lord Hailsham amendment likely to be the seventh.

A significant defeat for the government would come as a boost for rebel Conservative MPs who hope to stop the Lords’ amendments being overturned when the bill returns to the Commons.

Writing in The Independent, Labour’s Baroness Hayter, the Liberal Democrats’ Lord Wallace and crossbench peer Lord Hannay said MPs and peers have “both a right and a duty” to decide what sort of vote parliament should be given on the Brexit deal.

Addressing concerns it will only be given a vote if a deal is agreed, and not in the case of Britain leaving the EU without an agreement, they said: “The promise of a vote is only on the ‘final agreement’. With the prime minister maintaining that ‘no deal is better than a bad deal’, the offer would presumably not extend to a decision by the government to ‘walk away’ and let us fall out of EU membership.

“The absence of a deal would mean no protection for UK citizens living in the other 27 states, no rights for EU citizens living here, a hard border between the north and south of Ireland, and immediate customs duties on the flow of goods. Any such outcome must be taken by parliament, not just ministers.”

The peers added: “For any parliamentary approval process to be genuinely meaningful, this eventuality must be covered – and it is not by the government’s offer of a vote only on an agreement.”

The Lords had already passed an amendment that would have given parliament a more meaningful say on Brexit, but it was overturned by the Conservatives in the Commons.

In their article, Baroness Hayter, Lord Wallace and Lord Hannay said parliament must be allowed to determine what would happen next if it decides to reject the government’s agreement with Brussels, or if no deal is made.

They said: “For the promised vote to be meaningful, parliament would need to have a say on what happens next if the terms are rejected or if there is no deal. In either instance, it would be for the Commons to decide the next steps – not simply the government.

“The stakes would be high. There is no point speculating now on what the best course of action would be. So at this stage, we should not close off any options for what might happen – more time to negotiate, a pause in the process or anything else.

Confirming their support for Lord Hailsham’s amendment, they added: “We and others seek to ensure our country’s future should be determined by parliament. It seems extraordinary that we should even have to argue that case. Even more so that we should be called mutineers or saboteurs for upholding democratic principles.”