Speaking to The Sunday Times, Cameron said there would be “no going back” after a vote to Leave later this week, arguing that re-joining the EU would require the UK to join the eurozone and sign up to the Schengen borders agreement, and the surrender of rebates on Britain's contribution to the EU's budget.
“Once you have jumped out of the aeroplane, you can't scramble back through the door," Cameron said.
"Out is out and if you had buyer's remorse you could only get back in on the basis of joining the euro, Schengen and giving up the rebate and no-one is ever going to want to do that. this is an irreversible decision with very bad consequences for the British economy."
And the Prime Minister also rounded on Leave campaigners, accusing them of dismissing the anti-Brexit warnings of people including Bank of England governor Mark Carney.
“If you were about to get into your family car and drive your family at high speed on a motorway and the mechanic said to you, 'The brakes are faulty, the fuel is leaking, don't get in that car,' you would listen to that expert,” Cameron said.
“Would you take a risk with your family getting into a faulty car? You wouldn't.”
Cameron's warning comes as a YouGov poll for the same paper showed a one per cent lead for the Remain camp on 44 per cent.
Anthony Wells, director of YouGov's political and social research team, said the figures represented broader bounce back for Remain, with personal finance concerns becoming increasingly significant.
In a survey conducted over June 16 and 17, the pollster found that 33 per cent of Britons think their personal finances will be hurt by a Leave vote, up from 23 per cent a fortnight earlier.
Comparing the latest polls to the Scottish independence referendum, Wells said that last year's Scotland vote saw voters swayed by the prospect of change before a sharp correction back to the status quo in the final days before voting.
“Public opinion on the EU looks as if it may be moving in exactly the same way, with that same late shift to Remain as people attracted to the idea of leaving the European Union worry about the risk to their economic wellbeing,” he said.