Keir Starmer has admitted his three biggest mistakes since becoming Prime Minister, But in a message to Labour rivals hoping to take his place as party leader and PM, he said he had “much more” work to do. Sir Keir offered a blunt assessment of his early period in Number 10 in a 2,900-word essay, published in response to criticism from former Labour Prime Minister Sir Tony Blair.

The Prime Minister said: “Along the way we made mistakes – most obviously when setting the level at which to means test the winter fuel payment. We also asked a lot of the British people, particularly businesses who now pay higher national insurance contributions.

“And while we were right to be clear – both during the campaign and since – that it would take a while to turn the British oil tanker around, I do believe that the mood music in the early part of the Government was too negative. We should have shown the underlying hope of our direction much more clearly.”

One of the Government’s first decisions was to means test winter fuel payments of up to £300, previously available to all state pensioners, so that only those with incomes below £11,500 would usually be eligible.

Campaigners warned that this would mean people on the verge of poverty were denied the vital cash to stay warm in winter. The Government eventually u-turned and increased the means test limit to £35,000.

The second mistake was increasing National Insurance for employers by 1.2%. Labour insisted that because it only affected businesses – not employees – this allowed it to raise extra funding for the Treasury while keeping a manifesto pledge that “we will not increase National Insurance, the basic, higher, or additional rates of Income Tax, or VAT.” However critics accused it of breaking the promise, while businesses warned it had become more expensive to employ staff.

There has been no u-turn on this policy and the tax hike remains in force.

The final mistake was insisting in a speech, shortly after he became Prime Minister, insisting that “things are worse than we ever imagined”.

In a gloomy warning to the nation in August 2024, around a month after winning a general election landslide victory, Sir Keir said: “Things will get worse before they get better.”

But Sir Keir also set out his priorities for the future – including fixing the welfare system, an issue where his government has clashed with Labour backbenchers.

And he said a series of long-term policies “is all coming”, suggesting he intends to be there to carry them out,

He said: “Is there more to do? Yes. Much, much more. Is our welfare system in need of reform? Yes. Is our economy in need of even more growth? Definitely.

“Do we need bolder policies on everything from the European Union, to protecting our children online, and the difference we can make now in preparation for higher global energy prices in the winter? Yes, and that is all coming.”

Former Health Secretary Wes Streeting and Greater Manchester Mayor Andy Burnham are both thought to be planning leadership challenges, although Mr Burnham will only be able to stand if he wins the Makerfield by-election on June 18.

In his own essay earlier this week, Sir Tony claimed Labour was stuck in its “comfort zone” and lacked a “coherent plan for the country”.