Sir John Major says Brexiters are playing 'Russian roulette' with UK economy
Brexit campaigners are making "foolish" claims in their battle to win over voters and are playing "Russian roulette" with the economic future of the UK, Sir John Major has warned.
The former Prime Minister said he has "no doubt" that quitting the European Union would "harm our nation" for years to come as well as leaving the bloc "gravely weakened".
Sir John, who is on a visit to Hong Kong, said that investors had told him "almost without exception" that leaving was a "bad idea".
The consequences would be "bad for the UK, bad for Europe, and bad for the wider world", he insisted.
In a speech to the Credit Suisse Asian investment conference, he said the remaining members of the bloc would not reward Britain with a favourable trade deal if it leaves.
He said: "The UK will have chosen to leave and, by so doing, will have gravely weakened the whole EU. Some countries will see 50 years of ambition imperilled - and our partners will hardly wish to reward us for that.
"Any trade deal the EU might eventually do with us would certainly not be a sweetheart deal: and it may be harder and harsher than the optimists believe."
Sir John, whose premiership was dominated by bitter Tory in-fighting over Britain's membership of the EU, said he understood the frustrations over Brussels that fuel the Leave campaigns but insisted voters must "not let an emotional spasm of faux-patriotism overcome the realities of the modern world and spin us out of Europe".
He added: "The battle now joined over Europe has - on one side - the romantic nostalgia of an 'Out' campaign that aches for a past that has long gone, in a world that has moved on.
"On the other side those - like me - who wish to remain are not European dreamers: we are realists who see an edgy, uncomfortable world, and believe that the UK is safer, more secure and better off remaining with our partners in Europe.
"In the referendum, the easiest slogans inevitably lie with the 'Out' campaign, and repudiating their often foolish and extreme claims is for a UK audience. Suffice to say, the 'Out' advocates, whether in enthusiasm or ignorance, lace their argument with false statistics and unlikely scenarios.
"They promise negotiating gains that cannot - and will not - be delivered. They hail the purported gains of leaving Europe, whilst ignoring even the most obvious obstacles and drawbacks."
Vote Leave chief executive Matthew Elliott said: " John Major has been wrong on nearly every EU issue over the last 20 years.
"He said Britain should join the ERM (exchange rate mechanism) - that was a disaster which cost three million their jobs.
"He signed us up to Maastricht saying it wouldn't give up sovereignty and he refused to rule out joining the euro.
"Now he doesn't want to take back control and stop handing Brussels £350 million a week. He was wrong then and he is wrong now."