UK's ex-PM Blair calls on Labour to focus on policy, not personality

* Blair urges Labour to avoid moving left or ​reversing Brexit, focus ⁠on policy debate

* Blair criticises rivals Burnham ​and Streeting's proposed shifts left or EU rejoining

* Blair calls for pro-business stance, AI focus, cheaper energy, closer EU relationship

LONDON, May ​26 (Reuters) - ‌Tony Blair, who led Labour to victory in three UK elections, called on the party on Tuesday ⁠to shun the temptation to move left or reverse Brexit ⁠to shore up its fortunes, and to ​concentrate on policy rather than personality.

As Labour gears up for a possible leadership contest aimed at ousting Prime Minister Keir Starmer, Blair, who was the party's longest-serving premier between 1997 and 2007, spoke out in ​a ‌more than 5,000-word essay.

"(Any renewal of Britain) requires a fundamental reset," he wrote. "Labour's only electorally viable strategy is to become the Radical Centre."

Rivals to Starmer are circling the prime minister, who is battling some of the worst popularity ratings of any leader, and increasingly offering their opinions on ​how to turn round the ailing fortunes of a government that has struggled to offer voters a ‌clear vision or long-term plan.

"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'," he wrote.

"Whether there is a leadership change or not is irrelevant if it doesn't start with a policy debate."

He appeared to take aim at two leading challengers to Starmer - the ​favourite, Greater Manchester Mayor Andy Burnham, and former health minister Wes Streeting, by arguing against their mooted solutions to ‌Britain's myriad problems - a move to the left or an attempt to rejoin the European Union.

"It is one thing when in opposition to indulge this perennial delusion that when we lose seats to ⁠the right ⁠the country is really signalling it wants Labour to move ‌left; it is dangerous to do it in government," he wrote.

"Just as Brexit was never the answer to Britain's challenges back ​in 2016, reversing ​it isn't the answer to the country's far worse situation in 2026."

Instead, ‌the government should signal it is on the side of business in navigating the AI revolution, must focus on cheaper energy rather than cleaner energy and try to forge "a structured, formal relationship" with the EU. (Reporting by Elizabeth Piper; Editing by Sharon Singleton)