Green groups have urged the Government to slap a £1-per bag tax on peat-based compost in the Budget on 23 March.
Wildlife and conservation groups say peat bogs dug up for compost are responsible for 630,000 tonnes of carbon emissions every year.
The RSPB, Wildlife Trusts, Plantlife, Butterfly Conservation, the Irish Peatland Conservation Council, Buglife and Vital Earth are calling on chancellor George Osborne to introduce a peat tax.
RSPB conservation director Mark Avery said: “It’s incredible that a product as environmentally-damaging as peat is still being widely consumed in the UK.
“We have got rid of lead in our petrol, CFCs in aerosols and DDT in the countryside – so why is this dinosaur industry still lumbering along, causing damage to our environment?”
Chief executive of the Irish Peatland Conservation Council, Catherine O’Connell, said: “Our bogs need the levy. Irish peat bogs are being torn apart to supply British gardeners with bags of peat compost.”
The Government has set a voluntary target to phase peat out by 2020. However, a report by the RSPB claims “it’s not strong enough or quick enough to make a real difference”.
Head of science at the Royal Horticultural Society, Dr Roger Williams, said that introducing a “punitive tax would not necessarily have the desired outcome of reducing peat use”.
Roger said: “The RHS is acutely aware of the adverse environmental effects of peat use and how vital it is to dramatically reduce gardeners’ usage. That’s why our gardens are 97 per cent peat-free.”
He said research into getting the best results from peat-free compost and raising awareness of peat issues was the best way to change behaviour.
But technical director at compost giant Westland, Dr Jamie Robinson, dismissed the tax call as “scaremongering”.
“Manufacturers have made tremendous progress in reducing peat,” he said. “A tax would punish consumers at a time of austerity when many are trying to save money by growing-their-own.”
Celebrities aired their views on Twitter. Former Gardeners’ World presenter Alys Fowler wrote of the tax proposal: “A tax I completely agree with!”
But Toby Buckland disagreed. He Tweeted: “LPG and solar panels are subsidised, so I say remove VAT from peat-free compost. Punish gardeners? Bad idea.”