Sir Tony Blair has warned Labour against forcing Sir Keir Starmer to quit without having a proper policy agenda to follow him, in his first intervention since the party was plunged into a leadership crisis.
Sir Tony, who is the only Labour leader to win three general elections, argued the government needs a "fundamental reset" less than two years after it toppled the Tories in a landslide victory.
The prime minister's grip on power remains unstable, with Andy Burnham and Wes Streeting billed as possible contenders to replace him.
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Sir Tony said Labour is "lacking a project" and was "playing with the future of the country" in a 5,700-word essay published on Tuesday.
He stated a number of areas in which he disagreed with the government since it came into office in July 2024.
Sir Tony, whose decade-long tenure as leader ended in 2007, said Labour had held back business and growth since it won the election.
The former PM referenced the increase in employers' national insurance, the workers' rights bill, and the rise in minimum wage.
He also criticised the government's welfare spending and called for the state pension triple lock to be reformed.
Sir Tony said: "The Labour Party is playing with fire; or, more accurately, with its future, and that of the country."
He added: "The government's principal problem isn't Keir's personality. Or a failure to communicate 'our achievements'. Or a need to assert more strongly Labour's 'values'.
"It is because we don't have a worked out, coherent plan for the country in a fast-changing world and are in the wrong political position from which we can devise one and win a second term.
"The government is governing from an essentially traditional Labour 'soft left' position, parked firmly in the party's comfort zone."
Sir Tony argued the government should not have prevented the US from using its RAF bases during attacks on Iran.
He also said the party should do "whatever it takes" to stop the small boats crisis, laying out a 10-point plan for the future of government.
In it, he highlighted the impact of AI on society and called for action to be taken on this.
He said: "Without an agenda of this nature, radical but sensible, Britain will continue its long slide towards relegation from the Premier League of nations."
While he spoke highly of investment in infrastructure, planning reforms and immigration policies, he also detailed deeper shortcomings.
The Workers Rights Bill, an "acceleration of net zero", and phasing out of British oil and gas were noted as being particularly problematic.
Despite backing Remain in the Brexit referendum, and later a second vote, Sir Tony cautioned against any efforts to rejoin the European Union.
Instead, both should work on areas of shared interest, including defence and energy, he said.
"The truth is that Britain has lost from Brexit. But so has Europe," Sir Tony said.
"We're both weaker without the other. But we can't go back to cohabitation unless on a basis which enhances our capabilities, economic and political, and does not undermine them - and that goes for both of us."
(c) Sky News 2026: Labour needs 'fundamental reset', says Sir Tony Blair amid leadership crisis
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