Rishi Sunak said the UK can “stand tall” at the Cop28 climate conference as it remains a “leader” on tackling climate change despite his rollback of ambitions at home.

The Prime Minister also heaped praise on the King for his involvement in the annual UN climate talks in Dubai, saying Charles’ role attested to Britain’s authority on green issues.

Mr Sunak will announce £1.6 billion for international climate finance, including to support projects to halt deforestation and accelerate the transition to renewable energy.

But his attendance at Cop28 comes after he scaled back a host of pledges designed to help the UK reach net zero by 2050 and vowed to “max out” the UK’s oil and gas reserves by granting new North Sea drilling licences.

I will walk around very proudly tomorrow championing the UK's achievements in this space

Mr Sunak was asked as he flew to Dubai what he would say to those accusing him of being unserious about climate action.

“We’ve got a better track record than any other major economy in decarbonising,” he told journalists on the plane.

“Any which way I look at it, we are a leader on this issue. We have been, we’re continuing to do so. So I will walk around very proudly tomorrow championing the UK’s achievements in this space.”

It came after Lord Goldsmith, who resigned as his environment minister accusing Mr Sunak of being “uninterested” in green issues, told Sky News: “There’s no doubt our standing has diminished considerably in recent months.

“The UK is just not seen by our allies – big and also small island members of the commonwealth – as a reliable or serious partner.”

But Mr Sunak said the UK’s representation – from himself, Charles and Foreign Secretary Lord Cameron – “speaks again to our leadership on this issue”.

He said he was “delighted” the King, with his “longstanding track record championing this issue” – is delivering an opening address for the fortnight of talks.

Mr Sunak told reporters: “I’m delighted that he’s going to be at Cop tomorrow, he’s giving a call to arms in the opening statement and … it speaks volumes about our type of leadership as a country that we’ve got our head of state there, delivering a call to arms in the opening statement which speaks volumes about the respect that he’s got on this issue around the world.”

Mr Sunak defended his move to issue more licences for North Sea exploration, arguing that “the practical and sensible thing for the country is to make sure we use the resources at home as part of that sensible transition”.

Mr Sunak told broadcasters he meant “the people protesting outside my house” when he said he would not allow “ideological zealots” to dictate climate policy.

Sir Keir Starmer is also heading to the gathering in the United Arab Emirates (UAE) to stress that Britain would be open to green investment under a Labour government and position himself as a prime minister in waiting.

Asked about Sir Keir’s plans to make Britain the world’s green finance capital, Mr Sunak accused him of “just trying to catch up” as his Government already has a “fantastic track record”.

The Labour leader, who polls suggest is on track to snatch the keys to No 10 at the next general election, will be meeting world leaders and foreign investors at the conference.

Mr Sunak batted off questions on whether he fears Sir Keir appears more like a statesman, pointing to his own “fantastic track record” of global diplomacy over the last year.

“I feel pretty good about how we’ve conducted our foreign policy and engaged all our partners and allies around the world over the past year and delivered real benefits for the British people at home in investment and jobs and better security.

“And that’s what we’ll continue to do. That’s what I’ll be doing at this summit. I’ll be speaking to lots of leaders about things not just climate change, but also the situation in the Middle East.”

Reacting to news fighting has resumed in Gaza, the Prime Minister said he will call for “sustained humanitarian pauses” in meetings with regional leaders “so that more aid can get into the people of Gaza but also the hostages can come out”.

Cop28 takes place in the context of rising geopolitical tensions, with fears that the wars in the Middle East and Ukraine could make co-operation even more difficult.

The location of this year’s climate talks has prompted scepticism among many campaigners, as the United Arab Emirates is one of the world’s chief oil producers.

Cop28 president Sultan al-Jaber, who is also chief executive of state oil giant Abu Dhabi National Oil Company, has been accused of seeking to use the conference to strike oil and gas deals – which he has denied.

Asked whether the allegations undermine the UAE’s position leading the negotiations, Mr Sunak said: “No. Look, I commend the UAE’s leadership on this summit in general, we’ve been working very closely with them.

“In particular I’m really pleased that they’ve made incredible progress on the finance aspect of this.”

He said it was a “massive achievement” that a landmark deal to help the world’s poorest and most vulnerable countries pay for the irreversible impacts of climate change was agreed on the first day of the gathering.

The Prime Minister said he had not discussed the Cop28 summit with his climate-conscious daughter, saying they were too busy eating pasta and popcorn at the Downing Street Christmas market before his departure to Dubai.

But, he said, more generally he had a “very strong Conservative instinct to protect what we have for future generations”.

“It’s our moral responsibility to leave our kids’ environment in a better state than we found it, not just for my kids, that’s for everyone.”

Mr Sunak gave a lengthy response about children’s love of nature and his announcement this week of a search for a new national park for England and protection for urban wildlife havens and trees.