Chancellor George Osborne has said the warnings about the consequences of Brexit are not part of a “conspiracy” but a “consensus”.
Speaking at Stansted Airport in Essex, Mr Osborne said a vote to leave the European Union on 23 June would be a “one-way ticket to a poorer Britain”.
The Chancellor shared a stage with Liberal Democrat Vince Cable – who was business secretary in the Coalition government – and Labour’s Ed Balls – who was shadow chancellor under Jeremy Corbyn’s predecessor Ed Miliband.
Standing alongside his former adversaries, Mr Osborne insisted there was an “overwhelming consensus” among economists and world leaders that an exit would be bad for the UK.
It comes after Bank of England Governor Mark Carney said there could be a recession if the UK leaves the EU, while the International Monetary Fund said an exit could force up interest rates.
Mr Osborne accused the Leave camp of responding to these warnings by treating them as “a massive conspiracy”.
He said: “That’s everyone from Mark Carney to Christine Lagarde to Barack Obama to the entire editorial team at ITV to the staff at the IMF and OECD, to hundreds of economists, to a majority of leaders of small, medium and large firms – they think they are all part of some global stitch-up to give misinformation to the British people.
“The next thing we know, the Leave camp will be accusing us of faking the moon landings, kidnapping Shergar and covering up the existence of the Loch Ness monster.
“The response to the sober economic warnings from around the world by those who want to leave the EU has not been credible or serious.”
He added: “It’s not a conspiracy. It’s called a consensus.
“The interventions of the last couple of weeks, from the IMF to the Bank of England, make very clear that the economic argument is beyond doubt – Britain would be worse off if we leave the EU, British families will be worse off, equivalent to £4,300 a household.
“Leaving the EU is a one-way ticket to a poorer Britain.”
Mr Osborne also claimed 450 jobs and almost £1bn in investment announced by Ryanair would be “at risk if we left the EU”.
He said a new Treasury analysis showed that if the UK was forced to rely on World Trade Organisation rules in the aftermath of Brexit, it could expect to lose trade worth £200bn a year and overseas investment worth £200bn within 15 years.
Mr Osborne was speaking as more than 300 business leaders signed a letter urging voters to back Brexit, arguing the UK’s competitiveness is undermined by EU membership.
Vote Leave campaigner Boris Johnson said EU membership was favoured by “fat cat” bosses who exploited cheaper labour and took advantage of “remote and opaque” regulations to stifle competition and increase their own pay.