UK Prime Minister signs the letter that will trigger Article 50

UK Prime Minister, Theresa May is to trigger Article 50 today and as a result kick-start the Brexit process that will see Britain leave the European Union in two years' time. The UK voted to withdraw from the EU in a hotly contested and controversial referendum in June 2016 but formal "divorce" proceedings cannot begin until the Prime Minister officially informs Europe that the government is triggering Article 50.

That is expected to happen at 1.30 p.m. Wednesday (7.30 a.m ET) in Brussels, when Tim Barrow, the UK's permanent representative to the EU, delivers a letter of notification to European Council President Donald Tusk.

Theresa May was photographed signing the letter on Tuesday night.