Theresa May tells MPs: Accept the Brexit vote

British Prime Minister Theresa May told MPs to allow the government to carry out its Brexit plan or risk getting a worse deal in negotiations with the European Union.

Writing in The Telegraph, May said the government would stick to its Brexit timetable, which includes starting the formal process to leave the EU, early next year, despite the High Court ruling it couldn't do so without consulting parliament first.

May also warned MPs that public discussion of the government's Brexit strategy would lead to a worse outcome in negotiations, in her first major public statement since Thursday's court ruling.

"Now we need to turn our minds to how we get the best outcome for our country," May said.

"That means sticking to our plan and timetable, getting on with the work of developing our negotiating strategy and not putting all our cards on the table. That is not in our national interest and it won't help us get the best deal for Britain."

Three of the country's most senior judges, including Lord Chief Justice John Thomas, ruled unanimously on Thursday that May is legally required to pass an act of parliament before initiating Britain's formal withdrawal from the European Union.

The decision irked May, who said that an "important principle" of democracy is at stake as the government prepares to take its appeal to the Supreme Court.

The prime minister said the result of the June referendum was "legitimate."

"MPs and peers who regret the referendum result need to accept what the people decided," she said.

May could call a snap general election last year to bolster her standing in parliament and give her more sway over the Brexit process.