Only UK Parliament can give nod for Brexit

While officially the door remains open to Britain to stay, many on the continent would not welcome a U-turn now.

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

May had argued that her administration could trigger the departure process, without having to seek approval from lawmakers. But the Supreme Court disagreed.

The ruling is unlikely to halt or significantly delay Brexit, because lawmakers in Parliament are expected to approve Article 50, which May wants to invoke by the end of March. But it does open the door for lawmakers to influence the terms under which the country leaves, such as whether the U.K. remains part of the E.U. single market.

May appears to favor a so-called "hard Brexit," with Britain cutting virtually all ties with the E.U. But many members of Parliament favor a more moderate approach under which the country would maintain many economic ties, in order to have free access to the E.U. market. - Reuters