The row over how much of a say MPs should get in the Brexit process returns to the House of Commons later.
On Monday, the House of Lords again defeated the government over giving MPs a “meaningful vote” on the outcome of negotiations between the UK and the EU.
MPs now have to decide whether they agree with the Lords or with the government.
With several Tories threatening to vote against the government, numbers in the Commons are expected to be tight.
The UK is due to leave the European Union on 29 March 2019 and negotiations have been taking place over the terms of its departure.
The tussle between the Commons and the House of Lords – a process known as Parliamentary ping-pong – focuses on what happens if the UK government cannot or does not reach a deal with the EU.
The change to the EU Withdrawal Bill put forward by the Lords would give MPs a greater say in these scenarios.
Labour has urged its MPs to support the Lords’ amendment, describing it as the “last chance” for Parliament to guard against “a no-deal Brexit” which it says would damage the economy.
But the government says giving Parliament the power to intervene in negotiations would bind Theresa May’s hands in the talks.
Haven’t MPs already voted on this?
Yes – last week the Commons overturned a differently-worded House of Lords amendment on the same subject, after would-be rebels who support giving Parliament a greater role were given assurances that the government would take their concerns into account.
But the would-be rebels were unhappy at the government’s subsequent offer to meet their concerns, describing it as a “slap in the face”.
On Monday the government was defeated by 119 votes in the Lords, who tabled a new amendment which would mean MPs have to “approve” whatever the government decides to do if there is no Brexit deal.
MPs will debate and vote on these two rival amendments later when the bill returns to the House of Commons at about 15.30 BST.
The government has rejected suggestions it has tabled a last-minute amendment to deter any potential rebels, amid reports it was trying to “bundle together” the question of Parliament’s role with other matters on which it prevailed in the Lords into a single vote.
Theresa May’s Conservatives do not have a majority in the House of Commons, and ministers will be hoping Tory MPs unhappy at what has been offered so far do not decide to rebel this time.
As well as what the would-be Tory rebels choose to do, the number of Labour MPs voting with the government could also be a key factor.
The sticking points
The debate centres on what happens in three Brexit scenarios:
- If MPs vote down the UK-EU Brexit deal
- If Theresa May announces before 21 January 2019 that no deal has been reached
- If 21 January passes with no deal being struck.
Under these circumstances, the government has said, a minister will make a statement in Parliament, setting out the proposed next steps.
MPs will then vote on this statement. According to the government, this vote should be “on neutral terms”, with MPs simply noting what has been said.
But the Lords’ amendment goes further, saying MPs should have to “approve” the minister’s statement.
Appeal for unity
One of the expected Tory rebels, former justice minister Phillip Lee, said that talks were continuing between both sides ahead of the crunch vote.
He told the BBC that he and others were not trying to frustrate Brexit but to give a “sovereign” Parliament its rightful say in the process.
“This not about leaving or remaining or whether Brexit happens or not,” he said. “I am not interested in turning back the clock, what I am interested in is securing the best deal for Britain.”
Solicitor General Robert Buckland dismissed claims of talks with potential rebels and urged them to make a show of “national unity” ahead of a key summit of EU leaders next week.
He said it was “important to send a clear message not just to the world of Westminster but to Brussels that this is a prime minister…that can get vital legislation through about Brexit”.
EU has ‘serious’ differences with UK
Meanwhile, the EU has said there are “serious divergences” with the UK on a key issue in the negotiations – what happens to the border between Northern Ireland and the Republic after Brexit.
The UK and the EU have published a joint statement outlining the progress that has been made in the talks so far.
The EU’s chief negotiator, Michel Barnier, praised the “dedication and commitment” of the negotiating teams, and said progress had been made in “separation issues” like customs, VAT and the European nuclear agreement, Euratom.
Repeating his call for a “fully operational backstop” to prevent a hard border in Northern Ireland, he added: “Today marks a step forward in these negotiations. but a lot more work needs to be done before October.”