The attempt by a new association to establish standards for carbon-offset providers has been criticised by a rival company.
The International Carbon Reduction and Offset Alliance was set up in June, with co-chairman Jonathan Shopley warning last week that most offset providers would not qualify as members.
But Ben Hedley, director of UK offset company Clear, suggests ICROA was founded by firms that will miss out on accreditation by the government's environmental department Defra.
Hedley said: "The cynical among us suspect ICROA was set up because most offsetters will not qualify for Defra accreditation."
However, Hedley agrees with Shopley that "the cowboys" in the sector mean there is a need for common standards.
Defra is now expected to unveil details of a code of best practice for offsetting next month. The code was announced last year.
The department has confirmed it will only recognise offsets involving so-called Certified Emissions Reductions (CERs) - large projects overseen by the United Nations. Most offset providers deal in Verified Emissions Reduction schemes (VERs) which tend to be small scale and in developing countries.
ABTA is among many organisations to have expressed concern at Defra's policy.