Sir Keir Starmer has hit out at critics accusing Labour of lacking detailed policies, as the party prepares for a gruelling general election campaign later this year.

The Labour leader promised to meet the Tories’ “fire with fire” as he kicked off the new year with a major speech promising to boost growth and raise standards in British politics.

But Sir Keir and Chancellor Rachel Reeves continue to face questions about how Labour will reverse years of sluggish growth, with criticism too that the party’s pre-election platform remains light on major policies.

Speaking to listeners on LBC, Sir Keir said: “You can’t really say, ‘We don’t know what you stand for, we haven’t set anything out’. Unless you’ve just really not paid very much attention to what’s been said over the last year or so.”

We need to create the environment of stability

He pointed to “five big mission launches, big speeches, backing documents” to argue that his party’s offering to voters was clear.

Alongside plans to improve living standards, Sir Keir stressed plans to halve violence against women and girls.

Asked how he plans to deliver growth, he said he would “work with the private sector to invest in the future”.

He said investors want stability after several years of uncertainty and “chopping and the changing” in British politics.

“We need to create the environment of stability,” he added.

At the centre of Labour’s campaign is a £28 billion-a-year green energy investment, but the Labour leader has stressed it will be subject to the party’s fiscal rules.

Labour had promised in 2021 to invest £28 billion a year until 2030 in green projects if it came to power, but last year Ms Reeves said the figure would instead be a target to work towards in the second half of a first parliament.

Sir Keir called it a “confident ambition” on Friday.

It comes as Labour prepares to launch a fresh attack on Prime Minister Rishi Sunak over the two percentage point cut to national insurance due to come into force on Saturday, labelling it a “raw deal” because of hidden tax rises.

A Labour poster was unveiled on a shopfront and ad van in Wellingborough, where the party is seeking to overturn a Tory majority in an upcoming by-election.

Local MP Peter Bone was ousted from the Conservative Party and a by-election was triggered by local voters after his suspension from the Commons for breaching the MPs’ code of conduct.

The ad, which features a colourful image of the Prime Minister in the style of a mock shopping deal advert, will also be published online and in regional newspapers across the country.

Ms Reeves, who launched the advert in front of a crowd of activists, said it is “time for a fresh start”.

The national insurance cut, she said, is “a drop in the ocean – working people are worse off under the Tories”.

“Never have people paid so much in tax and got so little in return in the form of public services,” she said.

“This is the year of choice, the year the British people will give their verdict on Rishi Sunak and 14 years of Conservative government.”