Rules that would help to remove deforestation from supermarket shelves must go ahead “without delay”, a group of cross-party MPs and peers have said.

Under Government plans, businesses that have a global turnover of more than £50 million will be prohibited from using or selling goods containing palm oil, cocoa, beef, leather and soy that come from land linked to illegal deforestation.

The measures, which would also require firms to undertake a due diligence exercise on supply chains and report back annually, were first included in the Environment Act in 2021.

Environment Secretary Steve Barclay announced that ministers would introduce the necessary legislation needed to enact these measures during a Cop28 speech in December.

But the Government has yet to publish the legislation or set a date for the rules to come into force.

In a letter to Mr Barclay on Thursday, a group of MPs and peers – including Green MP Caroline Lucas and former Environment Minister Trudy Harrison – called for the rules to be brought forward urgently.

The letter said: “Despite much anticipation and some progress, more than two years later the secondary legislation needed to progress these measures has not been laid.”

It cited research from environmental organisation Global Witness which found that UK imports have been linked to deforestation almost twice the size of Paris since the Environment Act was signed into law two years ago.

“Further delay will exacerbate our national contribution to global deforestation,” the letter added.

“We believe with this legislation consumers could instead play a positive role in reversing environmental harms, by encouraging sustainable, fair and responsible purchasing.”

The group of MPs and peers urged the Environment Department (Defra) to bring both the due diligence regime and a robust enforcement system into effect as soon as possible, and no later than the start of 2025, with any grace period minimised.

They also called for Defra to accept and implement the Environmental Audit Committee’s report on tackling the UK’s contribution to global deforestation, including extending the scope of the due diligence regime to cover all deforestation and financial services.

Ms Harrison, who is chair of the Environment APPG, said: “The lack of forest risk commodities protections poses an existential threat to forests around the world.

“The UK showed global leadership at COP26 when it led a landmark global pledge to end deforestation. To build on this legacy, this legislation must pass as soon as possible.”

Other signatories include shadow nature ministers Olivia Blake MP and Alex Sobel MP as well as Liberal Democrat climate spokesperson Wera Hobhouse MP.

On Thursday, Mr Sobel also introduced a private member’s bill to Parliament for a new UK law that addresses the full extent of the climate and nature crisis in line with the most up-to-date science.

The Climate and Nature Bill, previously known as the Climate and Ecology Bill, has been co-sponsored by cross-bench MPs and has been backed by scientists, local councils, 500 organisations including the Co-operative Bank and Friends of the Earth, as well as broadcaster Chris Packham.

A Defra spokesperson said: “The UK is leading the way globally with novel legislation to tackle illegal deforestation to make sure we rid UK supply chains of products contributing to the destruction of these vital habitats.

“This legislation has already been introduced through the Environment Act and is just one of many measures to halt and reverse global forest loss.

“The Secretary of State set out the scope of planned secondary legislation at Cop28 in December; this legislation will be laid as soon as parliamentary time allows.”