LONDON — The Scottish government said Tuesday that it will ask Britain’s Supreme Court to block Prime Minister Theresa May from triggering European Union exit talks without consulting the Scottish Parliament first — another potential blow to May’s hopes of a quick divorce from the bloc.
The prime minister has said she plans to trigger two years of exit talks by invoking Article 50 of the EU treaty before the end of next March.
But last week the High Court complicated that plan, ruling in response to a legal challenge that lawmakers in Britain’s Parliament must first get a vote.
The government is asking the Supreme Court to overturn the judgment. The court said Tuesday that it will hear the case Dec. 5-8. In a reflection of the constitutional importance of the case — which hinges on the balance of power between Parliament and the executive — all 11 Supreme Court judges will hear the appeal.
Scottish First Minister Nicola Sturgeon said Scotland would also seek to intervene in the legal action, because ‘‘the consent of the Scottish Parliament should be sought before Article 50 is triggered.’’
She said Scotland’s top legal official, Lord Advocate Frank Mulholland, would make a formal application to the top court.
Britons voted by 52 to 48 percent on June 23 to leave the EU, but voters in Scotland strongly backed staying in.
Sturgeon, who heads the pro-independence Scottish National Party, has said she may seek a mandate for independence if Scotland is forced out of the bloc.