London Mayor, Boris Johnson made a suprising decision on Saturday morning. He sent an email to Prime Minister David Cameron, announcing his support to United Kingdom's withdrawal from European Union.

On the next day, he sent text message to prime minister Cameron, that he would campaign "leave" in the next referendum regarding whether United Kingdom should stay of leave in European Union. Shortly after, mayor Johnson spoke to the press outside of his home in London to formally announce his decision to support and campaign for "Leave EU."

In his text message, as reported by The Mirror, mayor Johnson told prime minister Cameron, "I've made up my mind. It's not about whether you love Europe or not. I love Brussels. I used to live in Brussels - fantastic city, wonderful place, and I love European culture and civilisation. But there should be no confusion between the wonders of Europe and holidays in Europe and fantastic food and friendships with a political project that has basically been going on now for decades."

Previously on Wednesday, according to The Daily Telegraph, one close political ally of mayor Johnson said he believed speculation over Mr Johnson backing "Leave" was a "choreographed game" managed by Downing Street.

However, during a press conference held outside his London home, as Washington Post reported, the former journalist said, "I don't think there is anything else I can do. I will be advocating Vote Leave — or whatever the team is called; I understand there are many of them — because I want a better deal for the people of this country, to save them money and take back control."

During his childhood, Boris Johnson lived in Brussel from 1973 to 1975, and went to school in European School of Brussels before he moved back to England. In 1989, he was appointed as Brussels bureau for Daily Telegraph. His assignment was to report events surrounding the European Commission.

During his tenure as a journalist in Brussel, Boris Johnson was known with his view that supported Euroscepticism. Many people who held such view were based on various reasons; some were fear about weakening of nation state with the integration, while other is the perception of undemocratic or too bureaucratic. While mayor Johnson said that his option to take side of leaving the EU was, "I now think [it] is in real danger of getting out of proper democratic control."

Known for his view of Euroscepticism, Boris Johnson finally made his decision to support Brexit. He has notified prime minister Cameron regarding his stance, and made an official announcement on Sunday.