“The time has come to change,” said Claude Bonard, 66, a Geneva resident and former senior bureaucrat. “A seed has been planted. Even if this doesn’t succeed, at least it’s started a debate.”

For supporters of the referendum, the idea of the Swiss citizen-soldier is anachronistic. They argue that Swiss gun laws are out of touch with much of the world and that restrictions would help reduce suicide and gun-related crime.

According to the World Health Organization, the Swiss suicide rate was 18.0 per 100,000 people in 2007. By contrast, the overall average rate is 10.1 per 100,000 in the European Union, according to W.H.O. data for 2004 to 2006. But the degree to which firearms have stoked suicide, and deaths more generally, is contentious, and data have been used by each side in the debate. For example, the Swiss suicide rate had been 25 per 100,000 in 1985, and there were only relatively minor changes in the federal gun laws over the period of the precipitous drop in the ensuing two decades.

Against the initiative stand an array of actors, including Parliament, the federal cabinet, and center-right parties like the Swiss People’s Party, the largest in the lower house, the Christian Democrats and the Liberal Party, as well as the powerful gun lobby ProTell, named after the iconic sharpshooter, and shooting clubs.

The government says it has already tightened gun laws, for example by banning storage of ammunition at home, restricting commercial sales and giving the police the power to confiscate arms. It argues that the cantons are already working on building and linking registries of arms.

Some opponents of the initiative fear an increase in black market trading if gun use is curbed, noting that gun crime in Britain has increased since restrictions were imposed in 1997. Others cite increased bureaucracy and costs to the state. Broader arguments range from the difficulty of interpreting a “need” for an arm to the removal of liberty, “Swiss values” and the breach of an unwritten compact between the state and the citizen.

“The vote poses a bigger question than guns,” said Martine Brunschwig Graf, a Geneva-based national lawmaker from the Liberals. “It’s about whether we want a society founded on freedom and responsibility.”