Swiss voters went to the polls on Sunday to decide whether the national intelligence service should be granted greater powers to spy on terrorist suspects and cyber criminals.
In Switzerland, where privacy is considered an important right, the intelligence service currently has to rely on information from public sources and from other authorities.
A majority of the 5 million Swiss voters are expected to approve the bill in light of recent terrorist attacks in Europe, according to a survey by public broadcaster SRF.
The government has drafted a bill that would allow agents to tap phones and computer networks.
Left-wing political groups have called for a referendum to stop the bill.
They warn that it would violate citizens' privacy, and that it would undermine Switzerland's neutrality as the secret service would also be allowed to cooperate with foreign agencies.
Citizens cast their ballots on two additional referenda on Sunday.
Environmentalists want the government to create a sustainable economic model by 2050. Although supporters of this plan have a majority, according to the survey, their lead has been shrinking and the adoption of the referendum looks uncertain.
In addition, unions have initiated a vote on raising government pensions by 10 per cent. The idea will likely be rejected on Sunday.