Tony Blair has said he cannot return to frontline politics because parts of the media would "move to destroy mode".
But the former prime minister said he is so "dismayed" by the current state of Western politics that he intends to play a significant role behind the scenes in shaping the political landscape.
Following mounting speculation about a possible comeback, Mr Blair said he will work to revive the "progressive centre or centre left" but has "no intention" of returning to the coalface of British politics.
In an interview with the New Statesman, he said: "What I'm doing is to spend more time not in the front line of politics, because I have no intention of going back to the front line of politics, to correct another misunderstanding ... but in trying to create the space for a political debate about where modern Western democracies go and where the progressive forces particularly find their place ... I'm dismayed by the state of Western politics, but also incredibly motivated by it. I think, in Britain today, you've got millions of effectively politically homeless people."
He added: "I can't come into frontline politics. There's just too much hostility, and also there are elements of the media who would literally move to destroy mode if I tried to do that..."
Mr Blair, who has made clear his desire for Britain to keep its "options open" over Brexit, said the process can be brought to a halt.
"It can be stopped if the British people decide that, having seen what it means, the pain gain cost-benefit analysis doesn't stack up. And that can happen in one of two ways. I'm not saying it will (be stopped), by the way, but it could. I'm just saying: until you see what it means, how do you know?"
The former premier said that while he would not have called the EU referendum, he was "forgiving" of the position David Cameron was in.
"When we thought we were going to have to hold a referendum on the Lisbon Treaty, I thought that was a very, very open question as to whether we were going to win or not," he added. "What it shows you (is) that if you put this decision to people like this in a referendum, I think at any point in time in the last 30 years you could have got that result."
Mr Blair denied reports that he had dismissed Theresa May as a "lightweight", describing the Prime Minister instead as "a very solid, sensible person".
"I didn't call her that (a lightweight)," he said. "This is completely not my view, by the way. I would not be rude and disrespectful in that way. I've not said that about her, I don't think that about her."
Labour has been "captured" by the far left, the former leader said, but denied describing Jeremy Corbyn as a "nutter".
"I did not call Jeremy Corbyn 'a nutter'," he said. "I don't think he's a nutter. I just think he is someone on the far left of politics and he's been consistent for the last 35 years that I've known him, which is fine."
Mr Blair called for lessons to be learnt from the vote for Brexit and Donald Trump's election as the next president of the United States.
"He won because people want to change," he told the magazine.
"If you leave aside all the comments that Donald Trump made and you just look at the two platforms, on the issues that related to culture and identity, I could see why there would be Americans, even in the centre ground, who might be attracted by that (Trump's) platform - even if, by the way, they weren't attracted by the personality of the person who is the standard bearer. There's got to be a lot of analysis as to why this happened."
The Leave campaign in the EU referendum created a "really interesting machine" that should be learnt from, he added.
In the wide-ranging interview, Mr Blair also praised Ed Balls, a key lieutenant of Gordon Brown at the height of the battles at the top of New Labour, for his stint in Strictly Come Dancing, saying he had "huge admiration" for the former shadow chancellor.