London - Britain's Industry Secretary Peter Mandelson had dyed green custard hurled at him by an environmental protestor opposed to airport expansion in London Friday.

The minister and former European Union (EU) Commissioner was walking to the venue of a low-carbon meeting in London when the incident occurred.

The custard, contained in a plastic coffee mug and dyed green for the purpose, was thrown by 29-year-old Leila Deen, a member of the Plane Stupid group campaigning against the construction of a third runway at London's Heathrow airport.

She was not arrested and told the BBC in an interview afterwards that it had been Mandelson who pushed through the expansion plans in January against opposition even from within the cabinet.

"When democracy is failing you have to resort to any means necessary as long as it is peaceful and does not harm other human beings," said Deen.

Mandelson described the protest as a "crude stunt" and said: "I am prepared to take my fair share of the green revolution on my shoulders but I am less keen on having it in my face." (dpa)