Brexit: UK enters 'tough' new era after leaving European Union

The UK faces tough negotiations with Brussels as the country reaches a "turning point" following Brexit.

Almost half a century as a member of the Brussels club came to an end at 11pm on Friday, with jubilant Brexiteers partying in Parliament Square in Westminster and a light show illuminating 10 Downing Street.

But even Boris Johnson acknowledged there could be "bumps in the road" as the UK moves into a new era, with uncertainty still surrounding the future relationship between Britain and its closest neighbours.

The UK's departure from the European Union became official at 11pm on Friday evening. Picture: Getty Images

"It is in our common interest to define as close and deep a partnership as possible in defence and security, and in police, judicial, environmental, scientific and cultural co-operation," he wrote in The Times.

"At the same time let me be honest, as I have always been: ease of access to the European market will depend on the degree to which the European Union's rules are accepted, because we cannot allow any harmful competition to develop between us."

With Big Ben silenced as a result of repair work, a projection of Parliament's clock was beamed onto 10 Downing Street and a recording of the famous bongs signalled the moment of the UK's exit from the European Union.

Outside Parliament, Brexit Party leader