Nearly 40 UK food businesses have threatened to stop sourcing products from Brazil over proposed land reforms.
An open letter from the group calls on Brazil’s legislature to reject a bill which could legalise the private occupation of public land.
The letter said the proposal could accelerate deforestation in the Amazon.
The bill is being considered just months after Brazil pledged to end illegal logging.
Sainsbury’s, Aldi, Greggs, the Co-Op, the British Retail Consortium, and the Hilton Food Group are among the major organisations to sign the open letter.
A vote in the Senate on the bill is expected later tonight (May 5) or tomorrow (May 6).
The companies say they “consider the Amazon as a vital part of the earth system that’s essential to the security of our planet, as well as being a critical part of a prosperous future for Brazilians and all of society.”
Rainforests are critical to mitigating the effects of climate change, as they store vast amounts of carbon.
Under President Jair Bolsanaro, the level of deforestation in the Amazon is reported as being the highest since 2008.
This year alone around 430,000 acres of the Amazon have been logged or burned, according to the Monitoring of the Andean Amazon Project.
The vast majority of land is cleared either to graze cattle for beef exports, or to grow soy, which goes in to animal feed around the world.
At a summit in April hosted by US President Joe Biden, Mr Bolsanaro declared that Brazil would end illegal logging. The letter says these measures “run counter” to this “narrative and rhetoric.”