Switzerland's Green Party and environmental groups are to challenge parliament's decision not to impose a moratorium on the use of genetically modified crops.
They say they now want to put the issue to a nationwide vote and let the Swiss public have the final say on the matter.
After a marathon 11-hour debate in the Swiss parliament, representatives narrowly rejected the proposed five-year moratorium by 90 votes to 83.
However, they approved fairly strict regulations on the planting and labelling of genetically modified organisms (GMOs).
The debate was the subject of intense lobbying in the parliament, with environmental groups like Greenpeace and agrochemical companies such as Syngenta battling for votes.
Environmentalists say they are particularly concerned that the final vote did not reflect the opinion of the Swiss people.
On Thursday Switzerland's Green Party announced their intention to hold a people's initiative on the issue of a moratorium - this time for the original demand of ten years, rather than the compromise of five which parliament rejected.
"If parliament is unable to represent the wishes of the large majority of the people, then the people will have to decide for themselves," said the Green Party in a statement.
Polls in Switzerland regularly show a majority of consumers are opposed to GMO products.
"We are very disappointed," Marian Künzle of Greenpeace told swissinfo. "Parliament did not reflect public opinion, instead it reflected the wishes of industry.
"It just shows how politics works nowadays; the pressure from industry is huge."
Boost for GM research
But Arthur Einsele, the spokesman on GMO issues for Syngenta, denied that the vote could be seen as victory for the Swiss agrochemical industry.
"Basically we are very pleased with the outcome of the vote," Einsele told swissinfo. "But it's not a victory for Syngenta, it's a victory for research in Switzerland."
Swiss organic farmers were among those fiercely lobbying for a moratorium. They fear their own crops could be contaminated as a result of GMO trials, thus damaging Switzerland's reputation as a producer of high quality organic food.
"I think this was a missed opportunity for Swiss agriculture," said Maya Graf, a member of parliament for the Green Party and an organic farmer herself.
"Our products are not cheap," she told swissinfo. "And our GMO-free status was a really important marketing advantage. Now we may have lost that."
GMO-free status to change
At the moment Switzerland is completely free of GMO crops, and the country's two biggest food retailers - Migros and Coop - do not stock GMO products.
Under the new regulations approved by parliament, however, that could change.
Planting of GMO crops for research purposes will be allowed under strict conditions: outdoor trials will only be permitted if it can be proved that the necessary research could not be carried out in a laboratory or greenhouse.
Parliament also left the door open for the growing of commercial GM crops, although the fact that there appears to be no market for GMO products in Switzerland means it's unlikely they will go ahead in the foreseeable future.
The debate in Switzerland was followed with great interest by Greenpeace Europe, which hoped that a Swiss moratorium might set an example for other European countries.
"Of course from a European point of view it would have been nice to have legislation in Switzerland which called for a ban. It would have reinforced our position," said Lorenzo Consoli, Greenpeace Europe's GMO specialist.
"But if there is a going to be a referendum things could change," Consoli told swissinfo. "Consumers will be able to say they want a moratorium."
In fact, if opinion polls are correct, and a majority of Swiss consumers really do not want GMO products, then the new regulations on labelling approved by parliament may achieve the equivalent of a ban anyway.
All products, including animal feed, refined products such as oil, starch, sugar and vitamins, will now have to carry labels indicating their GMO content, so consumers will be able to see clearly exactly what they are buying.
The rules are similar to those currently being proposed by Greenpeace Europe for European Union countries.
"The moment consumers and farmers are able to choose for themselves they will reject GMO products," said Consoli.
The issue of who would be held liable should anything go wrong following the planting of GMO crops in Switzerland remains complicated.
Although parliament voted in favour of a liability period of 30 years following plantings, it added a proviso that liability could only be considered if the original seeds were found to be faulty.
"This is a stumbling block," said Arthur Einsele of Syngenta. "Why should we at Syngenta be liable if someone applies the technology wrongly?
"We should have the same liability rules as the pharmaceutical or chemical industries."
The Green Party's Maya Graf was also dissatisfied. "I think that clause will make liability almost impossible to prove," she said. "We wanted much stricter regulations here."
Legislation not final yet
But since the Green Party has announced its intention to launch a people's initiative on a moratorium, all sides in the GMO debate will continue to have the chance to state their respective cases.
And, because parliament made so many changes to the original GMO law already approved by the Swiss Senate, the legislation will have to go back to the Senate for final approval too.
Lorenzo Consoli of Greenpeace Europe believes the long - and close - debate in Switzerland is a reflection of the concern right across Europe about GMO products.
"The fact is Europe and indeed the world are not ready to accept GMOs," he said. "And when Europe rejects GMOs, the world will follow."
swissinfo, Imogen Foulkes
To date, there have been no plantings of GMO crops in Switzerland.
Switzerland's two biggest food retailers do not stock GMO products.
Parliament rejected a moratorium on planting GMO crops by 90 votes to 83.