He also suggests some EU leaders are willing to consider changes to freedom of movement to accommodate the UK
Tony Blair has praised Jeremy Corbyn's performance in the recent UK election - despite the former prime minister being one of the most prominent critics of the leader of his former party.
However, he also warned the UK would be "flat on our back" if Mr Corbyn became prime minister.
While the Conservative party has retained power in the House of Commons as a result of a deal with the DUP, Labour surprised many by defying many polls and gaining 30 seats.
Blair - who was responsible for the centrist 'New Labour' approach in the 1990s - has frequently criticised Corbyn, and has even in recent years indicated his intention to return to politics and public life.
In an article released by his own Institute for Global Change, however, Mr Blair admitted he did not predict Labour's resurgence.
Mr Blair writes: "I agree Labour had a remarkable result which I did not foresee. I pay tribute to Jeremy Corbyn’s temperament in the campaign, to the campaign’s mobilisation of younger voters and to the enthusiasm it generated.
"His supporters shouldn't exaggerate it; but his critics including me shouldn't under-state it. He tapped into something real and powerful, as Bernie Sanders has in the USA and left groups have done all over Europe."
However, he also claimed his judgement hasn't changed over the 'risks' if the left-wing veteran becomes prime minister, and suggested the "determining factor" in the recent election was the Tory campaign.
Mr Blair argued: "If a right wing populist punch in the form of Brexit was followed by a left wing populist punch in the form of unreconstructed hard left economics, Britain would hit the canvas, flat on our back and be out for a long count.
"The Corbyn enthusiasm, especially amongst the young, is real, but I would hesitate before saying that all those who voted Labour voted to make him Prime Minister."
The former prime minister has been one of the most outspoken opponents of Brexit, and claims there is no evidence Britain "wants to pay a high economic price for Brexit".
He also suggests that he has had discussions with a number of European leaders who are "willing to consider changes to accommodate Britain, including around freedom of movement".