Canadian environmental groups on Wednesday accused Royal Dutch Shell, Europe’s biggest energy group, of reneging on its promise to reduce greenhouse gas emissions at its oil sands project in Alberta.

Pembina and EcoJustice said the company had won approval in 2004 and 2006 to extend its Athabasca oil sands project by promising to reduce emissions. Pembina yesterday presented the Alberta Energy Resources Conservation Board and government of Canada with a sworn affidavit stating Shell had set its Canadian oil projects the goal of becoming “less carbon dioxide-intensive than the most likely alternative, which is imported crude”.