Angela Merkel’s political party received three donations totalling €690,000 from the family that effectively controls BMW just as the German chancellor was lobbying fellow European Union leaders to block tougher exhaust emission standards for big cars, it emerged yesterday.

Details of the contributions – the largest private gifts to a German party in election year – were published on the Bundestag website a day after Berlin delayed a decision on the standards at an EU environment ministers’ meeting.

The German parliament revealed that Johanna Quandt, widow of Herbert Quandt, who transformed BMW into one of the country’s most successful carmakers, and her children Stefan and Susanne, each gave the Christian Democratic Union €230,000 on October 9. The three jointly own 46.7 per cent of the Munich-based company. They have been supporters of the party for many years, according to a statement from CDU headquarters. Ms Quandt and her children donated €450,000 immediately after the previous election campaign in 2009.