Tony Blair has said he and Jeremy Corbyn have a "profound disagreement" about the direction Labour should take on Brexit.
The former prime minister told ITV News it would be "perfectly democratic" to hold a second vote on Brexit as it was the country's most important decision since the Second World War and people should have "the right to rethink" once the full details of the new relationship are known at the end of negotiations.
But he admitted he is a figure of contempt for some people in the Labour Party and that he had not spoken with Mr Corbyn before his latest intervention.
Mr Blair wants Labour to take a different approach to Brexit, accusing the party of "timidity" and urging it to "make Brexit the Tory Brexit".
He told ITV News Political Correspondent Paul Brand: "I know there will be a lot of people criticising me for intervening on this at all, but my attitude is: it's a free country, I've got a right to speak, people have got a right to listen or not as they like."
Asked if his comments would be helpful to Mr Corbyn, Mr Blair said: "I don't know whether it's helpful or not.
"He and I have a profound disagreement about this. What he thinks it's best to do is carry through Brexit and what I'm trying to say to people like him and others in the Labour Party is if you carry on with this Brexit business, you'll be in the same position as the Tory Party.
"You're not going to be able to be spending your time on the health service over the next few years, if you win an election. You're not going to be spending your time on working out how you improve education, build infrastructure, make for a fairer society.
"You're going to be spending your time, as this Government is spending its time, on Brexit from the moment you wake up in the morning to the moment you go to sleep at night."
Mr Blair said it was now clear Brexit would cause economic difficulty and that other promises - such as extra funding for the NHS - would not be fulfilled.
The former prime minister said the public should be allowed to "think again" once the final terms of the new relationship with the EU were known.
"Over the course of this year we're going to have a chance for people to see what the alternative to present European Union membership is," Mr Blair said.
"Surely it's plain common sense to say you at least have the right to have a final say once you see the alternative. And if, by the way, you see the alternative and the country...says we still want to leave, fine.
"But surely we've got the right to have that say once we see what Brexit really means and really looks like."
Mr Blair also denied claims in a new book that he warned Donald Trump that UK intelligence agencies may have spied on his presidential campaign.
Mr Blair said the story was "literally a fabrication from beginning to end" and that the idea that the British intelligence services would interfere in a presidential campaign was "absurd".
- Watch Tony Blair's full interview with ITV News: