Tony Blair has said he feels "strongly" about the state of British politics and is considering whether there is a "role" for him in the future.
The former Labour prime minister told Esquire magazine he was concerned Britain had become a "one-party state".
He said the public faced a choice between a government pursuing a "hard Brexit" and an "ultra-left" Labour Party whose policies were out of date.
A spokesman for Mr Blair said he would not be returning to frontline politics.
Mr Blair merely wanted "to play a part in the debate because the true centre ground is vacant", the spokesman added.
He won three elections as prime minister after helping to transform Labour in the 1990s.
But his role in taking the UK to war in Iraq in 2003 alienated many in the Labour Party and the country at large and his conduct was criticised in this summer's official Chilcot inquiry into the war.
In the decade since leaving office in 2007, the former MP has focused on business ventures and his role as Middle East envoy - which he left in 2015.
Last month, the 63-year-old said he was winding down his consultancy business and focusing primarily on charity work.
This followed criticism of the lucrative contracts which he struck to advise multinational banks and foreign governments, including Kazakhstan.
Mr Blair, who has been critical of Labour's direction under Jeremy Corbyn, told Esquire that he was considering his own future and what role he could play at a turbulent time in British politics when the "centre ground" he represented was under threat.
"It's a tragedy for British politics if the choice before the country is a Conservative government going for a hard Brexit and an ultra-left Labour Party, that believes in a set of policies that takes us back to the 60s," he said.
"In the UK at the moment you've got a one-party state. When you put it all together, there's something seriously wrong.
"I don't know if there's a role for me... There's a limit to what I want to say about my own position at this moment. All I can say is that this is where politics is at. Do I feel strongly about it? Yes, I do. Am I very motivated by that? Yes.
"Where do I go from here? What exactly do I do? That's an open question."
He added: "There's been a huge reaction against the politics I represent. But I think it's too soon to say the centre has been defeated. Ultimately I don't think it will. I think it will succeed again.
"The centre ground is in retreat. This is our challenge. We've got to rise to that challenge."