A Tory frontbencher was forced to apologise today after expressing pride that he might have contributed to John Prescott's bulimia.

The shadow local government secretary, Eric Pickles, admitted he had been "silly" to mock the former deputy prime minister's condition at a party fringe event last night.

Pickles told the audience in Birmingham that he could sometimes be a "complete b**tard" to political opponents.

"When old Prescott came out as bulimic I thought, 'I wonder if I've added to that'," he said.

"I thought for a while, and I thought: 'Good'."

The joke was greeted with laughter at the meeting last night, which was organised by the Observer and focused on Pickles' political hinterland.

However, health experts warned today that the remarks were "dangerous", and could prevent sufferers coming forward to seek treatment.

Susan Ringwood, chief executive of the eating disorder support group Beat, said: "We are disappointed by this irresponsible and thoughtless comment.

"Any comments that might prevent someone from seeking treatment by trivialising the condition are potentially very dangerous.

"Eating disorders are a serious mental illness and still too often misunderstood.

"Mr Prescott was very brave and honest when speaking about his own condition and this has led to many more men seeking the help they need to beat their eating disorder."

The criticism led Pickles to issue an apology, saying: "This was a very silly comment that I regret."

Prescott revealed earlier this year that he had battled bulimia while serving as deputy prime minister.

He received widespread praise for raising awareness that the condition did not just affect young girls.