The vote is a serious setback to the government which want to relax export rules to allow the shipping of weapons to countries engaged in civil conflicts.
The government says such exports would only be allowed “if there is no reason to believe that the war materiel to be exported will be used in an internal armed conflict”. It argues the move is necessary to allow Switzerland's munitions industry to compete.
But MPs in the National Council voted 97-82 handed outgoing Swiss economy minister Johann Schneider-Ammann and the munitions industry a defeat, voting for a motion that would stop the government having sole power to change Switzerland’s weapons export rules.
The Swiss upper house, the Council of States, must now vote on the motion.
Whatever the fate of the motion in the smaller chamber of parliament, the vote by lower house MPs reflects serious concern in Switzerland over the issue of weapons exports.
During a debate on the issue, MPs noted Switzerland’s humanitarian tradition was on the line and that Switzerland’s neutrality was at stake.
The motion came before the National Council just weeks after a damning report suggesting Swiss weapons firms were using loopholes to circumvent weapons laws.
That report was made public just 48 hours after Switzerland’s SonntagsBlick newspaper reported Swiss-made hand grenades had been spotted in photos of a weapons stash of an ISIS sleeper cell discovered in August in Syria.
A spokesperson for state-owned arms manufacturer RUAG stated the grenades in those images appeared to be produced by the firm.