Instead of posing for photographs with far-right Brazilian politicians, ministers should be calling on Brazil to do everything they can to protect the rainforest.
A close ally of Prime Minister Boris Johnson has been criticised for failing to publicly speak out during a trip to Brazil about the damage being wreaked upon the Amazon rainforest by wildfires.
Labour's Barry Gardiner accused Trade Minister Conor Burns of "cosying up" to pro-deforestation ministers while on government business, and said he should instead have been calling on the country's right-wing leadership to do "everything they can to protect the rainforest".
Brazilian federal experts reported a record number of wildfires across the country this year - up 84 percent over the same period in 2018 - and environmental agencies have pointed the finger at the country's government.
Mr Burns posted on social media images of him drinking champagne with Brazilian minister Marcos Troyjo, who has backed President Jair Bolsonaro's policy of deforestation of the Amazon.
The Conservative MP for Bournemouth West called Mr Troyjo "superb" after meeting him to discuss "increasing trade and prosperity" between Britain and Brazil.
The Department for International Trade said Mr Burns, who is currently in Chile, had "raised environmental concerns in every meeting he has been in" since arriving in South America.
Shadow trade secretary Mr Gardiner said: "While Bolsonaro lets agribusinesses burn theAmazon, this week a UK Government minister has been busy cosying up to the Brazilian President's officials.
"Instead of posing for photographs with far-right Brazilian politicians, ministers should be calling on Brazil to do everything they can to protect the rainforest.
"The government must insist that Brazil honours environmental clauses in existing trade agreements and fulfils their commitments under the Paris Agreement."
Amnesty International blamed the Brazilian government for the fires, which have escalated international concern over the vast rainforest that is a major absorber of carbon dioxide from the atmosphere.
Brazil contains about 60% of the Amazon rainforest, whose degradation could have severe consequences for global climate and rainfall.
There has been a public outcry, including from politicians, environmental agencies and celebrities, about the record number of forest fires in Brazil this summer.
French President Emmanuel Macron has called the wildfires an international crisis and said the leaders of the G7 group of nations should hold urgent discussions about them during their summit in Biarritz, France, this weekend.
Mr Macron tweeted: "Our house is burning. Literally. The Amazon rain forest - the lungs which produces 20% of our planet's oxygen - is on fire."
The likes of singer Madonna, footballer Cristiano Ronaldo and Formula 1 champion Lewis Hamilton have spoken out about the fires raging in the rainforest.
The British racing car driver said: "More than a soccer field is being destroyed every minute everyday, the world needs to come together and help."
A Government spokesman said: "We are deeply saddened by the increase in fires in theAmazon rainforest. The impact of the tragic loss of these precious habitats will be felt around the world.
"The UK remains committed to protecting the world's rainforests and will continue to do so in Brazil through our International Climate Finance programmes.
"In meetings with the Brazilian government, Minister Conor Burns raised the UK's commitment to environmental protection and offered support to Brazil in the transition to renewable energy and a lower carbon economy."
Patrick Daly is the PA political correspondent.