Teachers who vowed to oppose military recruitment campaigns in schools were condemned by Labour and Conservative politicians last night.
The National Union of Teachers voted to back any school staff who want to boycott Armed Forces recruitment campaigns.
Representatives of the forces currently visit 1,000 schools each year to talk about careers. Delegates at the NUT's annual conference in Manchester lined up to condemn the tactics of the MoD in targeting teenagers with "misleading" information they said glamorises war.
The union backed a motion committing the NUT to "support schools in opposing Ministry of Defence recruitment activities based upon misleading propaganda".
One delegate said teachers should welcome a "crisis in recruitment" because it could force Britain to withdraw from Iraq and Afghanistan.
But the measure was condemned by Councillor Les Lawrence (Con Northfield), the cabinet member responsible for schools on Birmingham City Council. He said: "The NUT has exhibited their usual incomprehensible behaviour. The Armed Forces are an important pillar in the structure of our society."
Black Country MP John Spellar (Lab Warley), whose constituency includes schools run by Sandwell Council, said: "Many families in Sandwell have sons and daughters in the forces and are proud of them and the services that protect our country. I hope the council and schools in Sandwell will ignore the annual juvenile behaviour of the NUT and continue to encourage our youngsters to pursue a career in the service of this country."
Paul McGarr, an NUT delegate from east London, said: "They have had a crisis in recruitment and by taking this step we can add to that crisis, make it more difficult for this Government to launch an invasion alongside America of Iran and bring forward the day when we end the illegal occupation of Afghanistan and Iraq and bring all our troops home and safe to be back with their families and not in other people's countries where they don't belong."
The MoD insisted a career in the Armed Forces provided "unique opportunities".