Outgoing Mayor of London Boris Johnson has thrown his weight behind the campaign the leave the European Union, saying it is a chance to "vote for real change".
Mr Johnson, who is also a Conservative MP for Uxbridge and South Ruislip, said: "I want a better deal for the people of this country."
His decision to back to the leave campaign is seen as a massive blow to David Cameron and his stay campaign.
With various polls and bookmakers suggesting that Mr Johnson's support makes a Brexit more likely, cynics and critics have suggested that the current London Mayor has taken the stance to further his own political career, rather than because he believes in the reasons to leave the EU. They say that if his campaign to leave the Union is successful, it makes him the ideal to takeover as Conservative party leader when David Cameron steps down before the end of this Parliament, especially given the number of pro-Brexit MPs in the party.
In a 2,000 column for The Telegraph, Boris said: "There is only one way to get the change we need - and that is to vote to go; because all EU history shows that they only really listen to a population when it says no."
He added: "This is a moment to be brave, to reach out - not to hug the skirts of Nurse in Brussels, and refer all decisions to someone else.
"This is the only opportunity we will ever have to show that we care about self-rule.
"A vote to remain will be taken in Brussels as a green light for more federalism, and for the erosion of democracy."