A pacifist organisation has forced a nationwide vote to call for a ten-year moratorium on the planned purchase of fighter jets.
The group, Switzerland without an Army, handed in 107,000 signatures to the federal authorities on Monday. Under the Swiss system of direct democracy, any person or group can propose new legislation by gathering 100,000 signatures from eligible voters.
Campaigners, including the centre-left Social Democrats, argue that the acquisition of new fighter aircraft to replace 54 F-5 Tiger jets makes no sense and is too expensive.
They accuse the government of trying to move neutral Switzerland to the Nato military alliance.
However, opponents of the initiative argue it undermines Switzerland's security and is part of a piecemeal attempt to abolish the country's armed forces.
The government has already put off a decision until next year on how many aircraft to acquire and of which type.
A vote on the initiative is expected to take place in 2011.
A previous attempt by pacifists to block the purchase of fighter jets was rejected by voters in 1993.
swissinfo.ch with agencies