Courts decide who triggers Article 50

“Will she [the Prime Minister] confirm that there is really no basis in law to require the government to seek the permission of Parliament before invoking Article 50?”

Bernard Jenkin MP, 7 September 2016

“He’s absolutely right. The government’s position is very clear. This is a prerogative power, it’s a power that can be exercised by the Government”

Theresa May, 7 September 2016

Article 50 of the Treaty on European Union sets out how a country leaves the EU. The UK won’t begin the process of leaving until it sends an official notification under Article 50.

There’s a legal dispute about who in the UK has the power to do this. The Prime Minister’s statement reflects the advice of government lawyers that the government can send the Article 50 notification. Many other legal experts agree.

But equally respected lawyers argue that Parliament has to pass a law authorising this—giving MPs and Lords a vote that could block Brexit.

In the end, the courts will decide what the law requires, as Theresa May mentioned. A case on the issue is going be heard by the Lord Chief Justice and two other judges in October, with the losing side likely to be able to appeal directly to the Supreme Court.