UK says court erred in ruling Brexit needs lawmaker approval

Judges were wrong to rule that ministers must seek parliamentary approval before formally triggering Brexit, the U.K. government said as it outlined the case it will put in an appeal to the Supreme Court next month.

Three London judges said on Nov. 3 that the non-binding nature of the June 23 referendum made it a poor vehicle to impose sweeping changes on domestic law without a further vote of lawmakers. The government will appeal that decision in a hearing presided by all 11 judges for the first time. A ruling is due in the new year, according to the court.

“The divisional court erred in ruling that the Crown has no legal power to commence a withdrawal from the EU treaties,” the Department for Exiting the European Union said in a statement on Friday. The court should have ruled that “the Crown retains the power to give effect to the result of the EU Referendum.” That, it added, is “the constitutionally normal and unsurprising position.”

The decision undermined Prime Minister Theresa May’s plan to start the process of leaving the European Union by invoking Article 50 of the EU’s Lisbon Treaty by the end of March. If upheld, she’ll probably have to win a vote in both the House of Commons, where the majority of lawmakers campaigned for “Remain” in the referendum, and the House of Lords, where she doesn’t have a majority.

The judges ruled that the European Communities Act of 1972, which took Britain into the EU, meant that the government doesn’t have the so-called prerogative power to make the unilateral decision to withdraw, because triggering Brexit will “inevitably” change domestic law without Parliament’s approval. The Brexit department said that neither the 1972 act nor three subsequent laws explicitly or implicitly took away the government’s longstanding prerogative powers.

Allowing Parliament to vote on Brexit may delay the trigger or force May into making concessions to pro-EU lawmakers, as well as reveal more about her negotiating stance. While most pro-EU lawmakers have indicated they’ll uphold the referendum decision, many are trying to soften her stance. The Scottish National Party opposes Brexit, and the Liberal Democrats have said they’ll vote against Article 50 unless May guarantees a second referendum on the final exit package she negotiates with her 27 EU counterparts.