The government is under pressure to guarantee that imported biofuels meet environmental standards demanded inside the UK.
It comes after a Renewable Fuels Agency (RFA) report found that over 75% of biofuels used in the UK met no environmental standards whatsoever.
At the same time, however, three quarters of home-grown biofuels have delivered greenhouse gas savings of at least 44% against fossil fuels.
Henry Robinson, vice-president of the Country Land and Business Association, said there was no doubt UK-produced biofuels were best.
The CLA had worked closely with the government and RFA to ensure imported biofuels met the high standards commonplace in the UK, he said.
“There is a voluntary reporting system but this is clearly not working,” said Mr Robinson.
“Most biofuels can be traced in small quantities in conventional fuels, but the big oil companies say they dont know where their biofuel is coming from.”
UK motorists should not be expected to subsidise imported biofuels without clear environmental credentials, Mr Robinson said.
“The government must insist that the big oil companies meet UK environmental standards,” he said.
The CLA is also calling for a date from when uncertified biofuels will no longer qualify for Renewable Transport Fuel Obligation funding.