Leaving the European Union would be an "act of economic and political self-harm" which would leave the UK with a "second-rate" trading relationship, David Cameron warned.
The Prime Minister said leaving the single market would be "needless and reckless" and insisted that Brexit would not help the beleaguered British steel industry.
Mr Cameron said cutting ties with Brussels would "hit our service industries hard" as he warned that European governments would come under intense pressure to impose tariff barriers to protect their own industries from British competition.
Writing in the Daily Telegraph, the Prime Minister rejected the suggestion - previously made by Leave campaigners including Boris Johnson - that the UK could strike a trade deal like Canada's.
And he also rejected claims made by Mr Johnson that leaving the EU would give "more freedom to rescue the British steel industry".
The Prime Minister said: "We are doing everything we can to help British steel in these difficult times, but the idea that leaving Europe is the answer is a dangerous fallacy: more than half of our steel exports go to Europe."
He warned that Brexit could result in British airlines being unable to fly between Rome and Paris, the UK's farmers could be faced with a tariff on beef exports and telecoms firms and car manufacturers would be hit with trade barriers.
"This is the world we could wake up in if we leave Europe - with the massive knock-on effect on jobs, prices and living standards in our country.
"Because the longer this referendum campaign goes on, the clearer it becomes: those campaigning to leave Europe are inviting the British people to make an extraordinary choice - to be the first major economy in history to deliberately choose a second-rate, more restrictive trading relationship for its biggest market."
He said a Canadian or Swiss style deal would fall far short of the single market access the UK currently enjoys and any new trade agreement would face intense opposition in Europe.
"Governments in the EU would come under tremendous pressure from their domestic firms to discriminate against the UK. And who is to say they wouldn't take the opportunity?
"After all, why wouldn't the Spanish protect their largest telecoms provider? Why wouldn't the Germans try to give a leg-up to their insurance companies? Why wouldn't France adopt protectionist measures to penalise British banks?
"When you look at the consequences of leaving this market, you have to ask: why on earth would we do this to ourselves? I believe it would be needless and reckless - an act of economic and political self-harm."
His comments came as a poll indicated that Downing Street's tactics, labelled "Project Fear" by critics, were working, with the Remain camp on 51% and Leave trailing on 44%.
The Orb poll for the Telegraph found that only 5% said they are undecided, with those who currently say that they do not know how they will vote more likely to back the Remain campaign on June 23.
When certainty to vote is taken into account, the campaigns are virtually tied, with Remain on 49% and Leave on 48%.
Election guru Sir Lynton Crosby, who masterminded Mr Cameron's return to No 10, said ensuring their voters turn out will be crucial to either camp's chance of success.
Some 70% of Leave voters said they were certain to vote, while 61% of Remain backers will definitely cast their ballot.
Writing in the Telegraph, Sir Lynton said: "The fact that the Remain campaign are turning out a smaller proportion of the voters that support their cause, while current voting intention remains neck and neck, shows that the Remain campaign holds greater potential for success if it can effectively identify and motivate its supporters."
Vote Leave's chief executive Matthew Elliott said: "The greatest act of economic self-harm is that we send Brussels £350 million every week in return for handing control of our economy and democracy to EU judges.
"It is deeply regrettable that the PM is basing his campaign on doing down Britain and ignoring the free trade zone from Iceland to Turkey that we will be part of when we vote Leave."