Brexit campaigners are "prepared to sacrifice jobs" to secure their dream of getting Britain out of the EU, British Prime Minister David Cameron said.
Mr Cameron hit back at claims by Nigel Farage that the quality of life of voters was being ignored by a debate focused on the potential economic impact of leaving.
The Ukip leader and Prime Minister David Cameron were facing live television grillings on ITV ahead of the 23 June referendum on whether to break from Brussels.
Mr Farage - who was forced to defend his views on immigration in the face of a string of hostile questions from audience members - said GDP was not the only important measure.
But the PM hit back - after being confronted by a questioner who told him immigration meant he could not get a doctor, had three children in one room and had seen his home town become a "no-go zone".
"I would say really frankly that if we want to build houses, if we want to invest in our health service, if we want good schools for our children, we have got to strengthen and safeguard our economy.
"Coming out of the single market, which is what the Leave campaign want to do, that would damage our economy.
"Nigel Farage kept on talking about 'GDP isn't all that matters'. GDP is the size of our economy. It is the combination of all the wealth our country creates.
"He is basically saying it doesn't really matter. He is so keen to get us out of Europe that he is prepared to sacrifice jobs and growth along the way.
"We mustn't do that."
He went on: "There are good ways of controlling immigration and there are bad ways of controlling immigration.
"A good way is saying people can come here..but they have to pay in before they can get out.
"And when it comes to immigration from outside the EU - which of course is more than half - we do put a limit on the numbers for economic reasons.
Mr Farage insisted that the cost of European Union membership outweighs any benefits as he dismissed warnings about the potential economic impact of Brexit.
Even the "worst case scenario", with the French and Germans imposing tariffs on the UK, the barriers would be "significantly lower" than the amount paid into Brussels' coffers, he said.
He told the ITV referendum special that tariffs around the world had come down, reducing the benefits of tariff-free access in the EU.
"For the benefit of tariff-free access to a market that sells us more than we sell them, that regulates not just the 12% of the economy that sells to the EU but the other 88% as well, gives us unlimited free movement of people and bans us from making our own trade deals with the rest of the world - frankly the cost of membership now far outweighs any benefit," he said.
Mr Farage added: "No deal is better than the rotten deal we have got at the moment."
His comments came as he answered questions from an audience which will also grill the Prime Minister.
But Mr Cameron has refused to hold head-to-head debates with Brexit campaigners, leading Vote Leave to throw down the gauntlet to Mr Cameron earlier.
Vote Leave said a hastily-arranged press conference by the Prime Minister betrayed "panic" in the Remain camp and suggested he was "too chicken" to take on opponents directly.
In a joint statement, Michael Gove and Boris Johnson said the public "deserve the chance to hear these issues debated face-to-face between the Prime Minister and a spokesman for Vote Leave so they can judge for themselves which is the safer choice".
Mr Cameron has after declined to be grilled alongside other politicians, citing a desire to avoid "blue-on-blue" clashes with fellow Tories.
Deadline for registering to vote on Brexit
Meanwhile, the deadline to register to vote in the UK's upcoming referendum on European Union membership is midnight Tuesday.
Among those eligible to vote in the 23 June poll are Irish citizens aged 18 or over who live in the UK, Irish citizens born in Northern Ireland now living overseas and Irish citizens living overseas who have been registered to vote in Northern Ireland in the past 15 years.
British citizens currently living outside the United Kingdom who have been registered to vote in the UK in the last 15 years are also eligible to vote.
There is an online voter registration service for England, Wales and Scotland, while voters in Northern Ireland need to download and return a registration form.
