LONDON (Reuters) - A British exit from the European Union would set the country back half a century and be catastrophic for its trade and economic prospects, billionaire entrepreneur Richard Branson said on Sunday.
Branson, whose Virgin Group empire ranges from airlines to banking and space travel, was speaking after Prime Minister David Cameron told EU leaders last week he needed a new deal to keep Britain as a member.
Cameron has pledged to renegotiate Britain's relationship with the bloc before holding an in-out membership referendum by the end of 2017.
"We've now got a trading bloc that is equivalent to the size of America and we're on an equal footing when we're negotiating trade deals or airline deals," Branson told BBC TV's Andrew Marr Show on Sunday, referring to what he said were the advantages of belonging to the EU.
"If we go back to being Great Britain again we will have our hands tied behind our back and I think Europeans will rightly punish us and we'll be back to where we were fifty years ago."
Leaving the bloc would be "catastrophic" for Britain, said Branson, saying the EU had helped preserve relative peace in Europe.
Branson also said his home country might actually be richer if it had joined the euro zone.
"I think if we were part of the euro right now, our currency would be a lot cheaper. Great Britain would be doing that much better at trading in Europe. Because the pound is a lot stronger than the euro, it makes it more difficult for us."
None of Britain's main political parties is currently suggesting the country join the single currency.
(Reporting by Andrew Osborn; Editing by Greg Mahlich)
