(Bloomberg) -- The U.K. government’s lawyers had a difficult first day in a Supreme Court case that will decide whether Prime Minister Theresa May can execute her plan to start the process of exiting Europe as soon as March.
The 11 justices repeatedly challenged some of government lawyer James Eadie’s arguments that May doesn’t need to hold a vote in Parliament before triggering Article 50 of the Lisbon Treaty. The judges focused on the fact that lawmakers had approved the 1972 treaty that paved the way for Britain to join the EU, with one judge calling it a “joint effort.”
"If our accession was the result of a joint effort, should our departure not equally be so?" Judge Nicholas Wilson asked Eadie on Monday.
A loss for the prime minister might force May to disclose more information about her Brexit plans. She’s repeatedly told lawmakers she won’t elaborate on her negotiating stance to avoid giving her EU counterparts the upper hand. May wants to unilaterally trigger Article 50 to avoid a potentially time-consuming process of pushing legislation through Parliament.
“On your analysis, Parliament is effectively prepared to do whatever the government decides without expressing a view itself,” Judge Jonathan Mance told Eadie. “Is that realistic?”
Although Supreme Court judges often grill advocates to test their arguments, opponents of Brexit will seize on their comments as evidence they may side against the government. Lawyers observing the proceedings said that the tone of the questions indicated that the court was closely scrutinizing the government’s arguments.
Schona Jolly, an attorney at Cloisters in London, said in a post on Twitter that Eadie had faced some “uncomfortable challenges” on the differences between amending EU rights and withdrawing from the EU altogether.
"The issues are ones that divide the legal academy to some extent.," said Professor Jeff King of University College London. "Easy issues are not usually ones that go to the Supreme Court."
During his opening comments, Attorney General Jeremy Wright had framed the case as a simple matter of executive privilege. He said the prime minister’s power to negotiate dozens of foreign treaties a year under the “royal prerogative” without parliamentary oversight is “not a relic.”
The referendum was "conducted in the universal expectation, including in Parliament, that the government would implement the result," Wright said. The government’s need to maintain control of strategy and negotiations internationally is "clear and compelling."
A majority of lawmakers were against Brexit and although the consensus among them is that they won’t seek to challenge the will of the people, they may use the opportunity to force May to soften or at least better detail her approach.
The government lost the first round of the fight over Article 50, with the High Court in London ruling last month that Brexit would irrevocably change domestic U.K. laws, demanding a vote of Parliament under the nation’s constitution.
Wright quickly gave way to Eadie, who will argue the bulk of the government’s case over a day and a half. He said May, like the leaders of Australia, Canada, New Zealand and the U.S., have the wide discretion over foreign policy.
International affairs involve a myriad of decisions, judgment calls and negotiations, Eadie said, citing what another judge called "the power to act according to discretion for the public good."
If Parliament had wanted a vote on Article 50, it would have made one a requirement of the referendum legislation, Eadie said.
Enemies of the People
The case was initially brought by Gina Miller, an investment manager, and Deir Dos Santos, a London hairdresser, who both demanded a vote from lawmakers before implementing the non-binding referendum.
Miller arrived at about 9:30 a.m. Monday, flanked by lawyers and security guards as dozens of police officers formed a cordon across the front of the courthouse. Pro-Brexit group Vote Leave canceled a march led by Nigel Farage due to security fears.
"It is a sad day when space needs to be made at the highest civil court for security guards for parties and party anonymity is required to protect litigants seeking their legitimate right to bring this matter to court," David Green, a lawyer for Dos Santos, said before the hearing. "Neither the parties, including my client, nor judges are the enemies of the people," he said, referring to a newspaper headline following the initial ruling in the Brexit case.
Even without Farage’s march, dozens of protesters gathered outside the court’s building on London’s Parliament Square. About 20 pro-Europe activists dressed in full judges’ regalia rode atop a double decker bus while two pro-Brexit retirees held signs warning of an "establishment stitch up."
"Our vote is being hijacked by the elite," said Julia Waller, 71, as she waved a sign warning that the 11 judges were biased. "Here you have unelected judges and lords, old has-been politicians and celebrities who have vested interests in the EU and they don’t want to see Brexit going through."
The language outside was far more heated than inside, where the discussion was rapidly consumed by a 96-year-old case on the royal prerogative. The judges and Eadie spent hours debating Attorney General v. De Keyser’s Royal Hotel Ltd., a landmark ruling from the House of Lords -- where the judges sat until the establishment of the Supreme Court in 2009.
The case, unfamiliar to most without -- and even many with -- a law degree, limited the power of the government to seize property under the royal prerogative without compensation.
“What would be surprising is if a dispute about what the law is that is sat on by the largest bench in U.K. history would be dead easy for a non-lawyer to understand,” UCL’s King said.