David Cameron was also asked what he thought Britain would look like in 20 years time, if we choose to leave.
He said "I worry if we leave that we're going to see our economy suffer because we're going to lose access to the absolutely vital market that we have, and I would say the right thing to do, the British thing to do is to fight for a Great Britain inside a European Union, and don't take the Nigel Farage 'little England' option.
"That's not the country we want, it's not the country we want for our children, and I don't think it's right for our country."
Both David Cameron and Nigel Farage made some "eye-catching" claims surrounding the EU remain or leave campaign on Tuesday evening.
David Cameron and Nigel Farage have set out the cases for remaining in and leaving the EU in a live programme on ITV.
How did Nigel Farage and David Cameron fare on the EU Referendum programme? Farage reassured Leave, and Cameron dodged immigration - again.