Labour has questioned the “credibility” of the Government’s net zero strategy after it refused again to publish details of the flagship climate policy.

The Business Department has turned down Freedom of Information (FOI) requests from the PA news agency and New Scientist magazine to release a spreadsheet which details how individual policies in the strategy will deliver the carbon cuts needed to meet legal climate targets.

In a written question, Labour’s Darren Jones, chairman of the parliamentary Business, Energy and Industrial Strategy committee, called on the Government to reconsider the refusal.

Transparency and trust will be key as we transition to a net zero economy and the Government must be open with the public and with Parliament about what is going well and what isn’t

But energy and climate minister Greg Hands said information on policies which were “sufficiently advanced” would be published as part of annual updates on greenhouse gas emissions projections.

Mr Jones said: “The public have a right to know if the Government is delivering on its promises.

“Transparency and trust will be key as we transition to a net zero economy and the Government must be open with the public and with Parliament about what is going well and what isn’t.”

How can we take minsters seriously about cleaning up our energy system and decarbonising our economy when they can’t even come clean about how we’ll meet our net zero targets?

Shadow climate minister Olivia Blake said: “There are two reasons the Government could be refusing to publish the data on the contribution individual policies will make to reduce emissions: either ministers know the numbers don’t add up, or they simply don’t exist.

“Either way, this raises serious questions about the credibility of the Conservative’s net zero strategy. The UK is currently off track to meet our carbon budgets.

“How can we take minsters seriously about cleaning up our energy system and decarbonising our economy when they can’t even come clean about how we’ll meet our net zero targets?”

The UK has a legal target to cut greenhouse gases to zero overall, known as net zero, by 2050, with pollution reduced as much as possible and any residual emissions offset through measures such as planting trees.

A long-awaited net zero strategy for how the Government plans to meet the target, and carbon-cutting goals along the way in the 2020s and 2030s, was published in October, ahead of the key UN Cop26 climate summit in Glasgow.

It spells out a wholesale transformation for the UK, from phasing out boilers to heat homes in favour of low-carbon technology such as heat pumps, to ending conventional car sales, rolling out electric vehicles and on-street charging points, boosting offshore wind and planting more woodlands.

But while officials insisted at the time that the strategy would deliver the needed carbon cuts, the spreadsheet detailing the projected emissions reductions from the specific policies it sets out has not been made public – despite the FOI requests.

In his written answer to Mr Jones, Mr Hands said the Business Department (Beis) published updated projections for future energy use and greenhouse gas emissions in the UK each year, with a new set expected in “due course”.

“This will set out emissions reductions from those specific net zero strategy measures where decisions on the design of the associated individual policy intervention are sufficiently advanced to meet energy and emissions projections publication standards,” he said.

A Beis spokesperson said the net zero strategy set out “specific, detailed measures” that would be taken to transition to a low-carbon economy, including the shift to clean power, supporting hundreds of thousands of well-paid jobs and leveraging up to £90 billion of private investment by 2030.