The Government needs to introduce due diligence measures to stop commodities such as soy and palm oil grown in illegally deforested areas from entering the UK, WWF’s chief executive has said.

In an open letter to Prime Minister Rishi Sunak ahead of his speech at Cop28 on Friday, Tanya Steele said the lack of a due diligence regime undermines any commitment to protecting the world’s forests.

World leaders agreed at Cop26 in Glasgow to reverse the destruction of the world’s forests by 2030, which Mr Sunak is likely to mention in his speech on Friday.

Since that time an area of tropical rainforest twice the size of Wales has been cut down.

Ms Steele said: “As the architect of the Glasgow Declaration, it is deeply disappointing that the UK’s warm words and leadership on the global stage are yet to be turned into meaningful action at home to end the UK’s devastating contribution to illegal deforestation.

“The powers to create a due diligence regime were passed into law by the Environment Act in 2021 yet repeated delays between Government departments mean we still await the necessary secondary legislation.”

Restoring forests are seen as critical to preventing the climate heating to dangerous levels while stopping the collapse of ecosystems.

Habitat destruction has been the main cause of species becoming extinct in recent years, with some dying out before they can be officially described by science.

Rainforests are the most diverse ecosystems on Earth and provide oxygen for the entire planet, but the felling has shown no sign of slowing down in the last 20 years.

WWF believe that introducing due diligence measures would go some way to reversing this trend and would demonstrate to the world the UK’s commitment to forest protection.

Ms Steel wrote: “I urge you to heed the clear and repeated calls from the many UK businesses exposed to forest risk commodities in their supply chains.

“The transparency of an ambitious due diligence regime is essential to achieve the deforestation and conversion-free supply chains they and their customers expect to see, while supporting the farmers most impacted by climate change to produce the world’s food.”

A spokesman for the Department for Environment, Food and Rural Affairs said: “We recognise the importance of delivering our world-leading due diligence legislation in our Environment Act to help tackle illegal deforestation in UK supply chains.

“This is one part of a wider package of measures we have introduced to support the delivery of the historic agreement to halt and reverse global forest loss, agreed at the Glasgow Climate Summit.

“We will continue to invest in our international programmes to restore forests which have avoided over 410,000 hectares of deforestation to date, and support new green finance streams.”