Fleets wanting to offset their carbon emissions have been told they will be able to rely on a new code of practice and quality mark to ensure offset companies actually provide the services they claim to offer.

The carbon offsetting industry has already been told to create a common standard for their products in advance of the new code of best practice.

"It's important that consumers who want to buy carbon offsets with confidence can do just that,” said environment secretary Hilary Benn.

“When a consumer buys a tonne of carbon with the Government's quality mark, they'll know they're buying a full tonne of carbon."

However, environmental campaign group Friends of the Earth has urged caution arguing that the code will be of limited benefit.

“This code will still allow offsets to be sold for our increasingly polluting lifestyles,” said the group’s spokesperson, Mary Taylor.

She urged companies to produce less CO2 in the first place rather than looking for ways to offset it.

The government has admitted that there are still concerns about offsetting services, particularly in regard to whether any savings they produce would have happened anyway.

It also said carbon leakage – where emissions on one site are simply moved somewhere else – must end, and also that any emissions reductions are permanent.

But it rejected claims that the offsetting project would encourage more polluting practices.

"There are emissions that can't or won't be avoided, and that's where offsetting can play an important role,” said Mr Benn.

"That's why the Government is developing a code of practice and a quality mark for high-quality offsetting products to help businesses and individuals."

The Government has appointed AEA to become the accreditation body for the code.

The code will initially only cover offsetting products using Kyoto-compliant credits.

More information on the Code of Best Practice is available at www.defra.gov.uk/