UK Prime Minister David Cameron was forced onto the defensive on Sunday when an audience member at a televised 'Brexit' programme on the BBC likened him to Neville Chamberlain, a reference to a pre-war appeasement of Hitler.

"Mr Cameron. You say that your policy that you've negotiated with Europe cannot be over-ruled. It can. So are you really the 21st Century Neville Chamberlain waving a piece of paper in the air saying to the public 'This is what I have. I have this promise where a dictatorship in Europe can over-rule it?' Simple question - yes or no, please," asked audience member at BBC Question Time Show.

Cameron answered,"What I can tell you is the other 27 prime ministers and presidents have agreed it and they know if Britain votes to remain, they will implement it. And I think, you know, that this is not some empire and dictatorship."

"We're proving through this referendum that if Britain wants to leave this organisation, we can. We are a sovereign country. We choose to join NATO, we choose to join the EU. If we choose to leave, we can leave."

"But let's be clear - if we do leave, that's it. We are walking out the door. We're quitting; we're giving up on this organisation, which even if we leave, will have a huge effect on our lives, on our children, on our opportunities, on our businesses. I don't think that Britain at the end is a quitter. I think we stay and fight. That's what we should do."

David Cameron has compared his battle to keep Britain in the European Union to Sir Winston Churchill's fight against Hitler as he admitted he has to do more to win the referendum.

In his most passionate intervention to date, the prime minister urged people not to vote to leave on the basis completely untrue claims from the "Leave" camp. Cameron dismissed the accusation that the EU membership is costly.