Is consensus growing for a Parliament vote on Brexit?

Three top members of Britain's ruling Conservative Party are calling on Prime Minister Theresa May to drop her legal appeal of an earlier court decision and agree to consult Parliament on the details of the United Kingdom's departure from the European Union.

Ms. May has argued that her government has the right to trigger Article 50, by which the UK would officially begin its withdrawal, on its own. The three Conservatives — a former solicitor general, a former attorney general, and the former head of Brexit preparations — say she needs to let Parliament have a vote, and get on with the preparations.

Oliver Letwin, the former Brexit-preparation head, told the BBC on Saturday that going to Parliament with a "fast and tightly timetabled and constrained bill" would allow the government to kick off the process without taking control of the details out of the hands of government ministers. Otherwise, he said, they face the risk of letting Parliament have a voice in the negotiations, as the Supreme Court could decide to grant veto powers or other negotiating rights to lawmakers outside of the government.

All three agreed that Ms. May’s chances of winning the Supreme Court appeal of an earlier court decision were low.

“That way you avoid an unnecessary legal row, you avoid a lot of unnecessary expense, but you also avoid an opportunity for ill-motivated people to attack the judiciary, to misconstrue the motives of both parties to the lawsuit, and you provide certainty,” Edward Garnier, the former solicitor general, told the BBC. 

The growing pressure from within Ms. May’s own party to seek Parliament’s consent highlights an unusual convergence of interest between the leftist opposition and the hardline pro-Brexiters: while the government wants to keep an iron grip over the negotiations’ details, in part to box out influence from the leftist opposition, many pro-Brexit members of the body suspect that the government will water down the terms. And many of them have demanded that Parliament weigh in on the departure from the EU – for them its a means of recapturing the sovereignty of Parliament.

“I and many others did not exercise our vote in the referendum so as to restore the sovereignty of this parliament only to see what we regarded as the tyranny of the European Union replaced by that of a government that apparently wishes to ignore the views of the house on the most important issue facing the nation,” declared one pro-Leave Conservative, Stephen Phillips, in October. The government, he added, was pushing to negotiate in a way that was  “fundamentally undemocratic, unconstitutional and cuts across the rights and privileges of the legislature,” according to the Guardian.

Other hardliners have beat a different drum: warning that the government must not change course and decide not to invoke Article 50, after all. 

“I now fear every attempt will be made to block or delay triggering Article 50,” wrote then-Ukip leader Nigel Farage after the High Court ruled on Nov. 3 that May’s government could not do so on its own. "They have no idea level of public anger they will provoke."