Remain campaigners who say the EU is not perfect but there is no alternative are the "Gerald Ratners" of modern politics, Boris Johnson has claimed
London's mayor took a swipe at leading figures who suggest they are Eurosceptics but insist Britain must stay in the 28 member bloc.
Prime Minister David Cameron is among those campaigning for Britain to remain while admitting it is "not perfect".
At a Brexit rally in Manchester, Mr Johnson said one of the most "depressing things about the campaign to Bremain" is that "there is not a shred of idealism".
Likening remain campaigners who say they are Eurosceptics but there is no alternative to the jewellery tycoon who brought down his company when he described its goods as "crap", he said they insist the problems with Brussels are the "price we have to pay".
He said: "They keep saying that they are Eurosceptics, but we have no choice, we agree with you about the democratic problem, they say - but it's the price we have to pay.
"My friends, they are the Gerald Ratners of modern politics. The EU, they say - it's crap but we have no alternative. Well we do have an alternative, and it is a glorious alternative, a relationship with Europe based not on the whims of unelected bureaucrats but on cooperation between elected governments."
Mr Johnson warned that the June 23 referendum is the "last chance" many voters will have to decide Britain's relationship with the EU.
He said: "We should be in no doubt that this is the last chance many of us will have in our lifetimes to assert that principle in our relations with the EU. It is called democracy.
"Because it is now or never and if we fail to make the change now we will continue to be passengers locked in the back of a minicab driven by someone with a wonky satnav and taken to a destination we don't want to go and I think the people of this country have no idea how far the EU now invades every area of our lives."
He added: "It is time for us in Britain to speak up for the millions around Europe who think as we do, who are fed up with the remoteness of the Brussels system, but who are currently disfranchised.
"It is time for us to believe in ourselves, to believe in Britain and what we can do and if we hold our nerve and we are not cowed and we vote for freedom and democracy on June 23 then I believe that this country will continue to grow and thrive as never before and June 24 will be independence day."
Mr Johnson caused a live television news report to be disrupted when he called for supporters to interrupt broadcaster Michael Crick.
The Channel 4 News journalist was reporting from the hall while the mayor was still giving his speech.
Mr Johnson told the crowd: "Some chap from the media is trying to do his piece to camera. Shut up. Can we tell Crick, can someone go and interrupt Crick at the back
"Tell Crick you can do your piece to camera when I have finished."
A man from the crowd told Mr Crick to "be quiet" adding the Mr Johnson was "trying to talk".
The journalist replied that he was "just trying to explain what's going on" only to be told "yeah and so is he".