Keir Starmer has warned Boris Johnson that MPs will “do everything to stand in his way” if he tries to force through a “bad deal or a no-deal Brexit”.
Johnson, the frontrunner in the race to be Britain’s next prime minister, has suggested he will “disaggregate” Theresa May’s “otherwise defunct” withdrawal agreement and implement its less contentious elements.
But research commissioned by Starmer, the shadow Brexit secretary, from the House of Commons library suggests this would still require the government to bring legislation before parliament, which MPs could then reject or amend.
The library’s experts said: “Without an act of parliament, the UK cannot ratify the withdrawal agreement.”
They added that aside from “undertakings” the government gave that did not require changes to the law, “the UK cannot in any meaningful sense ‘implement’ individual parts of the withdrawal agreement otherwise than by primary legislation”.
Starmer said: “Boris Johnson’s Brexit plan is a non-starter. If he tries to force through a bad deal or a no-deal Brexit then parliament will do everything it can to stand in his way.”
The chancellor, Philip Hammond, earlier this week became the latest Conservative MP to signal that he could vote to block a no-deal Brexit, and will join a growing band of rebels on the Tory backbenches if he is sacked by the new prime minister as expected.
Starmer said: “Labour will work with all sides, even former members of Theresa May’s cabinet, to protect the country from a no-deal Brexit.”
Johnson’s team believe parliament would be unable to block a no-deal Brexit on 31 October because it remains the legal default.
But separate analysis by Labour suggests a string of emergency bills on issues from medicines regulation to new rules and systems for the border in Northern Ireland would still need to be passed, even in a no-deal scenario.
Any of them could potentially be seized on – and amended – by MPs looking for a mechanism to block a no-deal Brexit, or perhaps even revoke article 50.
Starmer said: “It’s simply unsustainable to sideline parliament on an issue of this importance. And it’s deeply irresponsible to ignore the legal black hole that a no-deal Brexit would cause.”
However, Johnson’s team insist they are likely to be able to persuade the EU27 to make changes to the withdrawal agreement, including the contentious Irish backstop.
They then believe Johnson will return in triumph to Westminster and win a majority for his Brexit deal in parliament.
Johnson hopes the threat to Tory seats from Nigel Farage’s Brexit party, combined with a perception that he – unlike May – would be willing to press ahead with a no-deal departure if MPs reject his agreement, will change the political mood.
This interpretation has been supported in recent days by several Labour MPs including Lisa Nandy and Gareth Snell suggesting they could vote for something similar to the withdrawal agreement if it were put before parliament.
Labour’s position, reiterated by Jeremy Corbyn in the Commons on Wednesday, is that any Brexit deal should be subject to a referendum.
He asked May: “Does the prime minister agree that whoever succeeds her should have the courage to go back to the people with their preferred Brexit option to end the uncertainty and get Brexit resolved?”
May responded by criticising Labour’s refusal to support her Brexit deal.
Starmer is one of the shadow ministers, alongside the key Corbyn allies Diane Abbott and John McDonnell, who are pressing for Labour to declare it would support remain in any such referendum.
But Corbyn has insisted he is continuing to consult on the issue. And he has made reference to the precedent set by the former Labour prime minister Harold Wilson.
Wilson called the 1975 referendum on common market membership when he was presiding over a deeply divided Labour cabinet, but while the government’s official position was to recommend staying in, he allowed ministers to campaign on both sides.
