Wes Streeting confirmed he will be standing, should a Labour leadership contest to replace Sir Keir Starmer be triggered.
“We need a proper contest with the best candidates on the field, and I’ll be standing,” he told reporters at a conference in central London on Saturday.
Mr Streeting, who this week stood down as health secretary, also insisted he did have enough support among MPs to trigger a contest, but suggested his challenge would “lack legitimacy” without rival Andy Burnham being given a chance to return to Parliament.
He told the Progress think tank conference: “Firstly, I do have support in the parliamentary party, but this week I also had a choice.
“We could have rushed straight into a leadership contest, knowing not all of the candidates would be on the pitch, that Andy Burnham was about to stand in a by-election, and that if we had rushed ahead without giving Andy a chance to stand, the new leader, whether it was me or anyone else, would lack the legitimacy, and so we would end up extending instability and uncertainty.
“That might have been the self-interested thing to do for candidates who are in parliament presently, but it wasn’t in the party’s interest and wasn’t in the national interest.”
Mr Streeting used his first speech since his resignation to warn Labour risks becoming the “handmaidens of Nigel Farage and the breakup of the United Kingdom” unless it changes course.
The former health secretary said: “The voters did more than send Labour a message last week, they issued a warning: that unless we change course, we risk being the handmaidens of Nigel Farage and the breakup of the United Kingdom.”
He also hit out at Labour’s course over the last few years, saying: “Corbyn’s leadership was marred by factionalism. The moral emergency of antisemitism in our party left little room for intellectual renewal or policy debate on the centre left.
“We then had a dishonest leadership contest, followed by an overcautiousness in opposition. Interesting policy ideas couldn’t be floated because we were too afraid of what the Tories might say, so we said nothing.
“Instead of a willingness to challenge ideas and kick the tyres, debate was viewed as division and shut down. As a result, we arrived in government underprepared in too many areas and lacking clarity of vision and direction.”
Referencing the brewing contest to replace Sir Keir Starmer, he said: “That’s why we need a proper contest where all candidates can put their best foot forward.”
In another major move, Mr Streeting called for Britain to rejoin the European Union.
“We need a bigger politics,” he told the Progress conference in central London.
He added: “Let’s embrace diversity of thought and competition for ideas as a strength. We won’t find radical solutions by ignoring ideas in favour of just problem solving – as though Government is the same as management consultancy – or if we believe that one person or one political tradition has a monopoly on ideas and wisdom.”
Leaving the European Union was a “catastrophic mistake”, Mr Streeting said.
He added: “In 2026, the British people increasingly see that in a dangerous world, we must club together, both to rebuild our economy and trade, and improve our defence against the shared threats from Russian aggression and America First.
“The biggest economic opportunity we have is on our doorstep. We need a new special relationship with the EU, because Britain’s future lies with Europe – and one day back in the European Union.”
