The British Supreme Court on Tuesday ruled that United Kingdom Prime Minister Theresa May must seek parliamentary approval to initiate the Brexit process, reported BBC. The verdict is being perceived as a blow to the government’s plan of invoking Article 50 of the Lisbon Treaty without getting consent from the members of Parliament. Article 50 allows a member state to leave the European Union.

The court said EU law is an “independent and overriding source” of the British legal system, as per the 1972 Act that was put in place when the country became a part of the European Economic Committee. It ruled that the Act will remain in force unless Parliament decides otherwise.

Supreme Court President Lord Neuberger held that the country’s exit from the EU will change the British Constitution to an extent, and such modifications cannot be made without an approval from Parliament.

The British government wants to start the process of the country’s exit from the European Union fold on March 31. Though the court held that the MPs have a say in the matter, it rejected the demand to let the Scottish Parliament, Welsh Assembly and Northern Ireland Assembly vote on Article 50 before it is triggered. “Relations with the EU are a matter for the UK government,” the court said.

Even though Attorney General Jeremy Wright said the government was “disappointed” with the verdict but would “comply” with it, a Downing Street spokesperson said the judgment would not change the government’s plan in any way. “The British people voted to leave the EU, and the government will deliver on their verdict - triggering Article 50, as planned, by the end of March. Today’s ruling does nothing to change that,” the spokesperson told BBC.

The UK had voted to leave the EU in a referendum on June 24, 2016, after which David Cameron, who had campaigned for the country to remain in the bloc, resigned as prime minister. The UK government had rejected a petition calling for a second referendum. May took charge on July 11 to implement the result of the vote along with her team