The Prime Minister was directly challenged about his position after the referendum, with one audience member on BBC's Question Time asking how he could possibly remain as Prime Minister if Vote Leave win.
"I promised this renegotiation, I carried it out," he said. "I promised a referendum, we're having it.
"I will take and obey the instructions of the British people, and on that basis I think it's right to stay."
Prime Minister David Cameron was asked why he held the referendum when he so fervently believes in remaining in.
He said, "I think some questions are so big, that it's right they are answered by the people and not the politicians.
"I don't think we should be frightened of the people making a decision and I'll accept that decision whatever it is.
He said that he believes such a decision to leave would be "irreversible".
"I think if we vote to leave, I don't think there's any prospect of rejoining," he added. "If you were trying to rejoin, you'd have to join the single currency, you'd have to join the Schengen no borders zone, you'd have to give up the British rebate."
He says it is a final decision: "You can't jump out of the airplane as it were, and scramble back into the cockpit hatch."
"Nobody wants to have cuts to public spending or putting up taxes," David Cameron said in response to David Dimbleby pointing out the Chancellor's threat of a 'Brexit Budget' on the BBC's Question Time special.
"I'm absolutely convinced that our economy will suffer if we leave," he said, saying that the single market is where "almost half of what we sell overseas goes".
"It stands to common sense" that growth and employment will suffer, he said.
He stressed that leaving the EU would leave a "hole" in public finances to the tune of "20 to 40 billion pounds", and that in response Britain will "have to" allow borrowing to rise, put up taxes, or cut spending.
Michael Gove has become the most senior Tory to announce he will oppose the emergency austerity budget the Chancellor intends to hold if Britain backs Brexit.
The move would mean the Leave campaigner would be forced to quit his Cabinet post as Justice Secretary.
The truth is, if we vote to Leave we will be in an economically stronger position. We will be able to take back some of the money that we currently give to the European Union and we can invest it in our priorities."
George Osborne is facing open revolt from Eurosceptic Tories, with Mr Gove becoming the 66th MP vowing to rebel against a new financial statement.
George Osborne has defended his stance on creating the Brexit budget.
Pro-Brexit Tory campaigners have reacted angrily to the financial implications the Chancellor has suggested in his manifesto, but when questioned by ITV News political editor Robert Peston, Mr Osborne said the EU vote was more important than his own career.
He said: "It's not about one politician or one career, it's about the future of our country.
"What's the point in getting involved in public life if you're not prepared to fight for the things that are really important to our future and our country?"
David Cameron defended George Obsorne's Brexit budget, following critisicm from Labour leader Jeremy Corbyn.
Speaking in the House of Commons during Prime Minister's Questions, he said the referendum was a "huge choice for our country", but added that "choices have consequences".
"If we vote out, the experts warn us we will have a smaller economy, less employment, lower wages and therefore less tax receipts - and that's why we would need to have measures to address a huge hole in our public finances.
"Nobody wants to have an emergency budget, nobody wants to have cuts in public services, nobody wants to have tax increases. But there's only one thing worse than not addressing a crisis in our public finances - and that's ignoring it."
Leave campaigner Nigel Farage has hit back at Bob Geldof in the Remain camp accusing him of "laughing at poor people".
The Ukip leader said Geldof's protest was "absolutely disgusting".
He told ITV News: "It's like rich people laughing at poor people.
"They are multi-millionaires happy to see the fishing industry [in Britain] go to the wall.
"They are there on their big boat effectively laughing at working communities being destroyed."
He also responded to Geldof's claims he had only ever attended one out of 43 meetings on the issue in European parliament saying they were a "waste of time".
"We've surrendered our waters and there's nothing we can do about it. You cannot do anything from within."
Labour leader Jeremy Corbyn has said his party will oppose any post-Brexit budget.
His comments come on the day George Osborne launched an 'illustrative budget' which highlights how far the economy could slide if the UK vote to leave the EU.
Mr Corbyn said Labour: "Would oppose any post-Brexit budget, just as we've opposed any austerity budget put forward by this Government."
"We're going to be voting to remain because it's the best way to protect families, protect jobs and protect public services.
Ironic cheers for Corbyn as he mentions the referendum. Says he won't back austerity budget. Also attacks Tories who are opposed to it...
Mr Corbyn criticised Conservative MPs who formulated the budget by stating they were "members who backed the bedroom tax, backed cutting disability benefits and slashed care for the elderly".
Hard to say whether Jeremy Corbyn was more annoyed about the threatened emergency budget or the Tories who might vote with him against it...
The Remain flotilla, led by Sir Bob Geldof, has branded Leave campaigner Nigel Farage a "fraud" who is "no fisherman's friend".
Shouting down a megaphone, Geldof accused Farage of only ever attending one meeting about the issue in European parliament.
He continued: "You're a fraud Nigel and you should go back down the river because you're up one without a canoe."
Sir Bob Geldof tells ITV News some "facts about fishing" as he goes head-to-head with Nigel Farage in an 'In and Out campaign-off' on the Thames.
The Boomtown Rats rocker urged voters not to listen to Remain campaigner Nigel Farage as he branded him a "liar" who "hasn't got a clue what he's doing".
"He's an opportunist of the worst kind," he said.