A complaint to the advertising watchdog by Guardian columnist and environmental campaigner George Monbiot has caused a national press ad claiming biofuels offer a sustainable alternative to oil to be banned.

The national press campaign, by the Renewable Fuels Association (RFA), was headed "Opec rakes in billions, but blames biofuels – confused?".

Copy in the ad formed an open letter to the president of Opec, the oil producers' cartel, from the "world's biofuels industries". The open letter offered a defence against accusations that the presence of biofuels in the market has caused a 40% rise in oil prices.

"We are proud of our efforts to provide a lower priced, renewable fuel to the world today," stated the letter. It ended with the line "Biofuels – a lower priced, sustainable answer to Opec's oil".

Monbiot, who has previously argued against the idea of sustainable biofuels in the Guardian, lodged a complaint with the Advertising Standards Authority that the RFA claim in the press campaign was misleading.