A landmark Supreme Court ruling tomorrow is unlikely to derail plans for Prime Minister Theresa May to begin Brexit talks before April – whatever the outcome.
The 11 Supreme Court judges will deliver their verdict on whether May needs approval from parliament to trigger the UK's separation from the European Union. The government has been appealing a decision of a trio of High Court judges, who ruled MPs must give the green light before Article 50 can be triggered.
However, heavyweight parliamentarians and senior City lawyers, one of whom is working on the case, expect the government to press ahead with the goal of triggering Article 50 in the first quarter irrespective of the result.
The political camp argues developments since the case began, including the Prime Minister promising a vote on the final deal, provide MPs with enough peace of mind not to contend the Article 50 trigger.
Meanwhile, legal eagles point out that the case, which relates to parliamentary sovereignty, is about ensuring the balance of power between the government and parliament remains in check, and is not about delaying Brexit.
John Redwood MP, a Brexiteer, told City A.M. he expected “four to five weeks of parliamentary process to put through a very short bill, that I'm told has already been drafted”.
Redwood added that May's speech earlier this month, in which she guaranteed MPs a vote on the final terms of Brexit, had overtaken many concerns.
“This case has been completely trumped by the actions of the Prime Minister,” Redwood said.
City of London MP and Remain supporter Mark Field agreed: “Realistically the issue has moved on a lot from the concerns that some held before Christmas”, adding he expects MPs to debate a Bill “within the next fortnight”.
Brexit secretary David Davis could introduce legislation less than 24 hours after the judges' decision according to a Westminster source.
One legal expert facing off against government at the Supreme Court agrees ministers could immediately issue brief legislation in the aftermath of the verdict.
David Greene, senior partner of Edwin Coe, who is acting for one of the case's respondents Deir Dos Santos, told City A.M.: “The Supreme Court could opine on what is required for this purpose and certainly a motion would not be sufficient...but in certain circumstances a one line Bill would be sufficient.”
Guy Lougher, partner and head of the Brexit Advisory Team at Pinsent Masons, said that “in principle, there is enough time to get an Act through parliament by the end of March”, adding that brief legislation would aid the process.
Opposition MPs will seek to amend a bill with conditions. Jeremy Corbyn hopes to add requirements for the Prime Minister to provide regular updates on negotiations. The Labour leader also wants to be sure parliament will vote on any deal before the European Council makes its own decision, providing time for a potential renegotiation.
And one Labour MP is seeking cross-bench support for a clause committing the government to seeking a “permanent equivalence” deal for the City.
However, Tory backbenchers warn against amendments that could interfere with negotiations.
“You can't pre-judge the negotiations. An amendment that looks at the outcome of the negotiation seems to be completely pointless,” said Brexiteer MP Kwasi Kwarteng