Teachers have attacked Ministry of Defence recruitment drives in schools, saying that teenagers often do not realise what they are signing up to.
The National Union of Teachers conference in Manchester will debate a motion calling for an end to the campaigns in England and Wales.
Delegates believe that children from deprived areas are "lured" in by sophisticated recruitment campaigns.
A spokesman for the Ministry of Defence said that they were invited to up to 1,000 schools a year and that teams went to raise awareness rather than recruit.
Catherine Brennan, a teacher from Croydon, who is presenting the motion, told BBC news: "They are too young to vote, too young to drink, too young to drive, but they are considered old enough to sign up for years in the armed forces without being fully aware of what they are signing themselves up for in their lives."
NUT general secretary Steve Sinnott told reporters before the conference that he was concerned youngsters from poorer backgrounds were being targeted.
"Youngsters from the most disadvantaged backgrounds have more limited opportunities in life than youngsters from better off backgrounds.
"It's simply a fact. I am not saying that youngsters from disadvantaged backgrounds cannot get something from a career in the military."
A spokesman for the Ministry of Defence said: "We do not recruit in schools.
"The single-service schools teams visit about 1,000 schools a year between them only at the invitation of the school - with the aim of raising the general awareness of their armed forces in society, not to recruit."
Feeds