According to the UK Supreme Court, Prime Minister Theresa May must get parliament's approval before she begins Britain's formal exit from the European Union.
As Reuters reports, the UK's highest judicial body dismissed the government's argument that May could simply use executive powers known as "royal prerogative" to invoke Article 50 of the EU's Lisbon Treaty and begin two years of divorce talks.
David Neuberger, President of the Supreme Court which ruled by 8-3 against the government, emphasized that despite the fact that the referendum is of great political significance, nevertheless, the Act of Parliament which established it did not say what should happen as a result.
"So any change in the law to give effect to the referendum must be made in the only way permitted by the UK constitution, namely by an Act of Parliament."