The case is a constitutional one, about the powers vested in the government, the crown and Parliament, which is supreme. The case is not about whether Britain will or will not leave the European Union, but about the procedure for invoking Article 50, which provides a two-year period for negotiations on the split.There's still an appeal to a higher court in the UK and "the ruling might ultimately be referred to the European Court of Justice."
The plaintiffs argued successfully that leaving the European Union involved the revocation of certain rights granted to Britons by Parliament, and that lawmakers must have a say and a vote before Article 50 is invoked.
In his ruling, the lord chief justice, John Thomas, said that “the most fundamental rule of the U.K. constitution is that Parliament is sovereign and can make or unmake any law it chooses.”
Oddly enough, this was precisely the case made by those who wanted to end membership, who argued that only by leaving the European Union could Parliament’s sovereignty be completely restored. Now that same argument could delay the very exit so desired by those politicians and their supporters.
November 3, 2016
"The British government’s plan for leaving the European Union was thrown into uncertainty on Thursday..."
"... after the High Court ruled that Parliament must give its approval before the process can begin...."