The UK will come back strongly to the world stage to “lead from the front” in tackling the climate crisis under a Labour government, Keir Starmer has pledged, after meeting world leaders at the Cop28 summit in Dubai. “There’s an overwhelming feeling here among world leaders that they want to see the UK back playing a leading role,” he told the Guardian at the UN climate talks. “That’s why our statement of intent that under a Labour government we will be back playing a leading role has been really well received. “And when we say leading on this, we mean leading by the power of example.” Starmer reaffirmed Labour’s commitment to invest £28bn a year on low-carbon efforts by the end of the next parliament, a target that has come under fire from the Tories and some members of his own party, and to complete the switch to clean power by 2030. “I have made an absolute commitment to clean power by 2030. That is going to be one of the driving missions of incoming Labour government. There’s never been any wavering from us, the £28bn is an important part of the investment towards that,” he said. “This is a real sense of mission under an incoming Labour government. We’ve only got five missions, one of them is clean power, so that’s how important it is to us.” He met John Kerry, the US special presidential envoy for climate, Hillary Clinton, a former US secretary of state, and António Guterres, the UN secretary general, on Sunday. Starmer spent three days at the summit, which was attended by more than 150 heads of state and government, meeting world leaders and ministers including Mia Mottley, the much sought-after prime minister of Barbados who is one of the stars of the talks, as well as Al Gore, the former US vice-president turned climate campaigner, and leading global investors seeking to put cash into clean energy in the UK. Sunak, by contrast, spent barely 12 hours at the conference, which is thought to be the biggest climate meeting yet. The UK prime minister held a handful of bilateral meetings, mainly with Middle Eastern states, including Jordan and Qatar. Starmer said: “People have really noticed that we have been here, working on this for two or three days now, and building those relationships, having the necessary discussions. And they compare that with the prime minister who flew in and flew out and was barely noticed whilst he was here.” He accused Sunak of retreating from the world stage and hiding behind the achievements of predecessors. Sunak has repeatedly claimed to be a “climate leader” based on the UK’s emissions cuts, but the vast majority of those reductions were achieved under previous prime ministers. The UK is now on track to miss its targets. Starmer said Sunak had used “what the UK has done as a sort of shield against us doing anything more. [I would] use it as a lever on the international stage”. However, Starmer has not pledged further cash to developing countries, which they need to cope with the impacts of the climate crisis. Labour has said it expects Sunak to deliver the cash to developing countries promised by Boris Johnson, amounting to £11.6bn by 2025, but if the party is elected Starmer will come under strong pressure to come to future Cops with much bigger promises of support. Labour also accused Sunak of breaking the UK’s longstanding cross-party consensus on the climate crisis. “We want to restore that cross-party consensus, but the way we will do it is by leading from the front,” said Starmer. “Those that want to be with us on this journey are very welcome. And I know there are leading lights in other political parties who would welcome an incoming Labour government leading from the front.” Zac Goldsmith, the Conservative peer and a former climate minister, predicted many like him would heed the call. “Sunak’s decision to fracture the cross-party cooperation we have enjoyed for years was not only politically inept – his polling nosedived soon after – it was morally repugnant and did the country and future generations a huge disservice,” he said. “Keir Starmer is absolutely right to commit to rebuilding it as prime minister and I know he will be able to rely on plenty of cross-party support.” Sunak has been accused by prominent Tories, as well as international observers and Gore, of undermining the Cop’s key goal of phasing out fossil fuels through his massive expansion of oil and gas licensing in the North Sea. Cop28, which is being hosted by the United Arab Emirates, opened last Thursday and will finish on 12 December. Negotiators and high-ranking officials from several countries at the summit told of their frustration and anger with the UK’s climate stance under Sunak. For decades, the UK has taken a central role at UN climate summits, hosting Cop26 in Glasgow in 2021 and leading negotiations on behalf of the whole EU in talks that led to the landmark Paris agreement in 2015. At Cop28, the UK has been “largely absent”, “disappointing” and “undermined by its leadership”, according to senior negotiators. “They have squandered the legacy of Cop26,” said one, voicing a common concern.