"People I work with echo my disgust that Canadian politicians are now using Canadian Forces personnel, past and present, to threaten people into voting Liberal," said one airman from Cold Lake, Alta.

The airman, who has served for 26 years, wrote in the e-mail to a national veterans' group that the ad appears directed at least partly at immigrants whose experience with militaries are almost invariably negative.

"We can only see this as a desperate attempt to win a few votes from what some would call the ethnic minority," he said.

"We have been honoured to walk Canadian streets. We have gone to the aid of municipalities in ice storms and the odd snow flurry in Toronto. If a city asked us for armed help during a crisis (as in the Oka or FLQ incidents, both a Quebec problem), I hope we would serve Canada well."

Retired colonel Alain Pellerin called the ad an act of desperation that is particularly "despicable" since CF members - even the chief of defence staff - are muzzled and cannot publicly respond.

"To use the Armed Forces for a purely crass political aim, to me is despicable," said Pellerin, a former infantryman who heads the Conference of Defence Associations, a lobby group and think tank.