Three months after the Swiss parliament approved the legalisation of abortion, opponents this week pushed ahead with plans to force a nationwide vote on the issue. They handed in the necessary number of citizen's signatures, collected by different groups.
Under the Swiss constitution, 50,000 valid signatures are required to challenge a new law.
Pro-life groups said they managed to get more than 120,000 citizens to state their opposition to the decision by parliament. The signatures were handed over to the Federal Chancellery in Bern on Thursday, which will have to approve them.
On Wednesday an alliance of the Christian Democratic Party - one of the four parties in government - and another grouping announced they had collected 53,000 signatures to force a referendum.
The Christian Democrats have their strongholds mainly in Catholic regions. But they failed to win enough support and agreed to team up with a group representing Protestant citizens.
The different organisations and parties are united in their opposition against parliament, but their views on abortion differ considerably.
The Christian Democrats want to ease the abortion laws only if mandatory counselling is introduced at the same time. The pro-life groups are against any moves to legalise abortion in Switzerland. They also put forward a separate proposal to ban terminations altogether.
Parliament in March decided to legalise abortion during the first 12 weeks of pregnancy. The decision came after years of political debate and was aimed at trying to find a uniform solution for regulations currently in place in different parts of Switzerland.
Abortion is technically illegal under a law dating back to 1942, unless a woman's health in danger. In practice, however, more liberal solutions have been introduced over the past few years.
Up to 13,000 abortions are carried out in Switzerland every year. Experts say the number of terminations has dropped by about 20 per cent compared with the 1970s.
Most countries in Europe, including all of Switzerland's neighbours, have made abortions legal in the early stages of pregnancy. Restrictive legislation is in place in traditionally Catholic countries, Spain, Portugal, Poland and the Irish Republic.
swissinfo with agencies