Tesco is facing pressure to distance itself from the world’s top meat producer over its links to deforestation in the Amazon rainforest.

Environmental activists at Greenpeace plan to target Tesco and its shoppers from Wednesday through an online campaign, in an effort to get the supermarket chain to end its relationship with subsidiaries of Brazil’s JBS.

Brazil will enter its annual fire season in August and data from its National Institute for Space Research showed blazes in the Amazon, the world’s biggest rainforest, grew to 6,804 in July, a 28% increase from a year earlier.

While only a small percentage of the UK’s beef imports come from the Amazon region, Tesco is a key customer of poultry supplier Moy Park Holdings and pork processor Tulip, both of which are owned by a US firm JBS owns a controlling stake in.

Tesco said it’s unfair to target companies that JBS has only bought recent interests in, while the grocer has a 40-year relationship with the suppliers.

Greenpeace accused Tesco of failing to tackle deforestation by pushing back its 2020 zero-deforestation pledge to 2025. It said the UK’s biggest retailer should set a target to halve the amount of meat it sells by 2025 to tackle climate change.

In response, the grocer said it backed the campaign to end deforestation but would continue to work with the companies. It also urged the British government to set a new law that would require companies to investigate their supply chains for links to deforestation.

“Moy Park and Tulip also supply Aldi, Co-op, Lidl, Sainsbury’s and Waitrose,” Tesco said in a statement. “Blacklisting them could lead to thousands of job losses, impact British farmers and ultimately compromise our ability to offer fresh British meat and chicken to our customers.”

JBS is starting to see investors and companies push back over its approach to deforestation. Last week, Nordea Asset Management said it would divest from JBS because of Amazon fires.

The government of Jair Bolsonaro put a four-month ban on fires in the region following pressure from foreign investors. Deforestation in the Amazon has surged in the past two years since Bolsonaro came to power with a promise to open up the world’s largest rainforest to further agriculture and mining.

“JBS is committed to ending deforestation throughout its supply chain and we have been at the forefront of the industry in taking steps to improve supply chain traceability in Brazil,” a company spokesperson said.

All of its subsidiaries of JBS must stick to strict procurement policies and share its anti-deforestation commitment, the company said.