Prime Minister Rishi Sunak’s plans to maximise North Sea oil and gas production give the impression he is “not being serious” about tackling climate change, a senior Tory has said.

Former cabinet minister Sir Alok Sharma, who was president of the international Cop26 climate summit hosted by the UK, said he will not support the Offshore Petroleum Licensing Bill when MPs vote on it later.

He said the legislation is a “smoke and mirrors” exercise which reinforces the perception that the UK is “rowing back from climate action”.

The Bill will require the industry regulator to run annual rounds for new oil and gas licences, subject to stringent new emissions and imports tests.

Currently licensing rounds are run when the North Sea Transition Authority (NTSA) decides it is necessary.

The Government claims the introduction of regular licensing for exploration will increase certainty, investor confidence and make the UK more energy-independent.

But the legislation has already triggered the resignation of former net zero tsar Chris Skidmore as a Tory MP and now Sir Alok has added his criticism.

Sir Alok said the legislation is a “total distraction” and “a smoke and mirrors Bill which frankly changes nothing” except to further damage the UK’s international reputation on climate action.

He told BBC Radio 4’s Today programme: “What this Bill does do is reinforce that unfortunate perception about the UK rowing back from climate action – we saw this last autumn with the chopping and changing of some policies – and actually not being serious about meeting our international commitments.”

He said that, at the Cop28 summit in December, the UK signed up to a global plan to transition away from fossil fuels but “this Bill is about doubling down on granting more oil and gas production licences”.

“It’s actually the opposite of what we agreed to do internationally, so I won’t be supporting it.”

Sir Alok said the Climate Change Committee has been “pretty clear that continued expansion of new oil and gas reserves is inconsistent with our climate commitments”.

A group of 30 politicians, including Mr Skidmore and Lord Goldsmith, have also written to Energy Secretary Claire Coutinho urging her and the Government to drop the Bill, saying that it is “diametrically opposed” to the global consensus of moving away from fossil fuels.

They said it will not achieve the Government’s aim of improving energy security as it cannot control the intentions of private companies who wish to sell the oil abroad.

Further North Sea oil and gas development would only damage the UK’s reputation on climate change, harm marine wildlife and enrich fossil fuel companies, the group said.

Instead, the Government should increase the supply of renewables and energy efficiency measures, it added.

The legislation, coupled with Mr Sunak’s decision to delay transitioning away from petrol and diesel cars and gas-fired boilers – which he said would save consumers money – has caused unease among Tory environmentalists.

Mr Skidmore, who led a Government review of net zero, announced on Friday that he would stand down as he said the Prime Minister’s environmental stance is “wrong and will cause future harm”.

Mr Sunak defended his decisions and insisted the UK was still a world leader in its net zero commitments.

Challenged about “flip flopping” on the issue at a PM Connect event in Lancashire he said: “We’ve already decarbonised faster than any other major economy in the world. Fact.

“We’ve got more ambitious targets than any other advanced economy in the world. Fact.

“And we can still meet those targets without having to impose these costs on you prematurely, telling you to switch your car, rip out your boiler, upgrade the efficiency in your home.”

The Offshore Petroleum Licensing Bill will have its first Commons test on Monday night.

Labour has opposed the measure, arguing it will not deliver benefits in terms of lower costs and improved energy security, is “entirely incompatible with the UK’s international climate change commitments”, and is “a totally unnecessary piece of legislation which will do nothing to serve the UK’s national interest”.

Sir Keir Starmer said the legislation was an attempt to create a political dividing line with Labour as the country prepares for a general election.

“What you’ve got is a Government that’s wasting its time trying to pass legislation to create a dividing line with the Labour Party rather than to solve the problem,” the Labour leader said.

Downing Street declined to say whether the aim of the Offshore Petroleum Licensing Bill is to increase the number of licences granted.

“I’m not going to speculate on whether more licences will be granted, that’s a decision partly for the companies themselves,” Mr Sunak’s spokesman told journalists.

Challenged over the fact the oil will be sold abroad rather than reserved for the domestic market, the official argued is is “preferable to have an international market which has more oil and gas from the UK and other countries which are stable, which are not authoritarian regimes”.