The shadow foreign secretary, David Lammy, has taken his green diplomatic policy for a test spin in Brazil this month in the hope that “climate justice” can serve as an international rallying cry for a future Labour government. In an interview with the Guardian, Lammy said a Labour victory at the next general election would allow Keir Starmer to build a partnership for radical climate action with Brazil’s president, Luiz Inácio Lula da Silva, before the UN’s Cop30 climate summit in Belém in 2025. “It could be a very exciting, progressive moment where they could jointly move forward in a deep and long-lasting way, not just for the sake of our two countries but for the sake of the planet,” Lammy said. “The global community has been missing the UK being serious about these issues for some time.” Lammy is attempting to put clear green space between Labour’s foreign policy and that of the Conservative government led by Rishi Sunak, who was criticised for initially intending to skip last year’s climate summit in Sharm el-Sheikh, cutting the UK’s aid budget to 0.5% of GDP when he was chancellor, and approving a raft of new oil and gas drilling licences in the North Sea. Lammy, by contrast, has spent much of the past year pushing a “green foreign policy” that is intended to echo the “ethical foreign policy” of the former Labour foreign secretary Robin Cook. He said he wanted to make the climate emergency one of the priorities of the United Nations security council, to introduce the concept of “ecocide” into international law, to restore UK foreign aid to 0.7% of GDP and to build a “clean power alliance” of countries committed to renewable energy that would act as a counterbalance to the Opec oil cartel. In Brazil, Lammy has discussed these and other ideas with the foreign minister, Mauro Vieira, and senior officials from other ministries in Brasilia, as well as visiting indigenous and agro-forestry communities in the Amazon rainforest with the NGO Conservation International. “What I detect in Brazil is that it wants a serious partner in the shape of the UK,” Lammy said on a video call from Santarem. “We haven’t had that in the UK. We have got a prime minister at the moment who is using the climate emergency as a political football. He has just granted a whole stack of new licences to drill oil in the North Sea. That has come up in conversation here in Brazil because it sends exactly the wrong messages from the global north.” The Labour party has been accused of softening several of its green pledges. Earlier this year, the shadow chancellor, Rachel Reeves, said Labour’s much-vaunted £28bn-a-year green prosperity plan would be delayed to the second half of a new Labour administration. Starmer also blamed the extension of the ultra-low emission zone (Ulez) anti-pollution scheme in London for the party’s narrow byelection loss in Uxbridge and South Ruislip. Labour has promised not to issue any new oil and gas licences in the North Sea but would still allow production at existing sites to continue for 20 to 30 years. That is unlikely to persuade countries such as Brazil that they should forego opening up new fossil fuel drilling sites. Lammy acknowledged his Brazilian counterparts were consistent in calling out “what they sometimes see as hypocrisy in parts of the global north”, but he said it would be too onerous for Labour to negate existing licences. “I can tell you as a lawyer that those licences have huge commercial implications once granted and they are extremely costly to unpick. That makes it very difficult during a cost of living crisis in the UK and with inflation running at 6.7% … but we will not grant new licences. That is the leadership people want to see.” Lammy said he had witnessed distressingly high levels of deforestation on his trip to the Amazon, and praised Lula’s success in reducing the damage during his first six months as president and committing to a goal of zero-deforestation by 2030. However, he was less enthusiastic about the European Union’s important contribution to achieve that target through the introduction of deforestation-free trade rules. Asked if the UK might adopt equally stringent controls, Lammy suggested a future Labour government would look more sympathetically towards Brazil’s complaints that such regulations were onerous. “We are not part of the European Union and I detected from the Brazilians that this gives the UK more flexibility because there have been issues between the EU and the Brazilians. That is a discussion I am willing to have with the Brazilians,” he said. Overall, he said, his aim was to boost bilateral trade, which is currently at a low level. Brazil is one of the top 10 economies in the world, yet ranks as the UK’s 35th biggest trading partner. In response to the suggestion that many voters would be alarmed if an increase in trade came at the expense of strong controls on goods linked to deforestation, Lammy insisted this would not be the case. He said the focus needed to be on climate justice, job creation and opportunities to reduce inequality while improving the environment. The shadow foreign secretary, whose family roots are in neighbouring Guyana, said the key was to protect the livelihoods of the custodians of nature, who had long been under pressure from an extractive economy model that exploited people and the environment with little heed for the long-term consequences. Nature needed to be a focus of diplomacy, he said, pointing to his call for a cautionary pause on deep-sea mining and his “passionate” support for the Amazon. “My foreign policy will be pursued as a green foreign policy,” he said, insisting he was in step with Starmer and the shadow climate secretary, Ed Miliband. “Our commitment to the environment is central to the way we look at the world.”