Media playback is unsupported on your device Media caption Ex-chancellor tells James Landale why he backs EU exit

Former Conservative Chancellor Norman Lamont has come out in favour of an EU exit, saying the upcoming referendum is a "once-in-a-generation opportunity".

Writing in the Telegraph, the peer insisted the UK could succeed economically outside of the EU.

And he argued that a vote to leave would give Britain control of its immigration, and boost democracy and accountability.

Voters in the UK will decide on 23 June whether to remain or leave the EU.

The government is campaigning for the UK to stay in a reformed EU, saying it will be stronger and safer by being a member of the bloc.

Lord Lamont, who was chancellor of the exchequer between 1990 and 1993, said reaching his decision had been "extremely painful... not least because of the prime minister", who used to work for him as a political adviser.

"But I have nonetheless come to the view that in this once-in-a-generation opportunity Britain," Lord Lamont wrote in the Telegraph.

'Contempt for democracy'

He said Mr Cameron "probably got as good a deal from the EU as anyone could" in his renegotiation of Britain's terms of membership of the bloc.

But he warned that "whatever barriers Britain erects against integration, the EU will always push for ways around them" - saying it had "repeatedly demonstrated contempt for democracy".

"Voting to remain in will not be voting for things to remain the same. The EU will continue to integrate come what may," he said.

Lord Lamont dismissed claims made by the Remain campaign that withdrawing from the EU would harm British trade and access to the EU single market.

"What is forgotten is that the EU needs an agreement just as much as we do," he said, adding: "Britain would have its own arrangement suited to our circumstances."

He also said Britain had "lost control of its borders", arguing that there was "no economic case" for "immigration in the hundreds of thousands".

The Conservative Party is deeply spit over the EU referendum, with about half of its MPs supporting an EU exit - against the PM's recommendation.

Five cabinet members, including Work and Pension Secretary Iain Duncan Smith, are backing the Vote Leave campaign group, as is London mayor Boris Johnson.