Ian Murray and Martin Whitfield, two Scottish Labour MPs, have expressed their intentions to rebel against by Jeremy Corbyn, and vote to keep the UK in the EU single market.
The pair said they would be using their votes in the Commons to support remaining in the European Economic Area (EEA), and a called on the party leader to reverse its Brexit policy.
Their opposition follows a government defeat in the House of Lords, when almost half of Labour peers ignored the party whip to push through an amendment to the EU Withdrawal Bill.
The bill is expected to return to the House of Commons within the next two weeks.
On Wednesday, a spokesperson for Corbyn said that Labour wanted “a new relationship” with the single market. “We’re trying to make the case for a Brexit that puts the economy and jobs and living standards first and to unite as much of the country on both sides of the Leave/Remain divide together in negotiating a jobs-first Brexit,” the spokesperson said.
“The EEA membership includes a number of different types of relationship, but it’s not what we are proposing.”
Mr Murray – who resigned as shadow Scottish Secretary in a protest against Corbyn’s leadership – and Mr Whitfield said in a joint statement that they believe the fight against a hard Brexit “is far from over”.
“Labour peers have forced the Prime Minister to give MPs a vote on remaining in the European Economic Area, and when that time comes we will vote in favour of doing so,” they said.
“We know we will be joined by many of our party colleagues from England and Wales, other opposition parties and a number of Tory MPs. If the Labour leadership wants to, we can now stop a hard Brexit in its tracks.
“There is no such thing as a good Brexit, but if we are to leave the EU then the least-worst option – to protect jobs and defend rights – is permanent UK membership of the Single Market.
“We urge our colleagues in Scottish Labour and the Labour leadership at Westminster to stand up for workers and defeat Theresa May’s destructive Brexit.”
On the other side of the House, Foreign Secretary Boris Johnson said he was “completely in conformity” with the government’s Brexit policy after he dismissed the Prime Minister’s preferred option for customs as “crazy”.
He added that he had not breached the ministerial requirement for collective responsibility, because the government’s approach to customs is yet to be decided.
“I’m completely in conformity with Government policy on the matter I believe which he is referring since that policy has yet to be decided,” he said.