The moratorium does not apply to research into GMOs (Genetically Modified Organisms) nor does it stop the import of genetically modified food.

But its supporters say the victory is a clear signal that Swiss consumers and farmers are in favour of GM-free food and produce, at a time when traditional Swiss farms are under threat from cuts in agricultural subsidies.

"All the farmers' organisations were behind this proposal, which they see as a chance for Swiss agriculture," Daniel Ammann, a spokesman for the winning coalition of GMO crop opponents, told Reuters.

"Swiss farming was already very ecologically sound and animal-friendly, and farmers are convinced now that with the added label of 'GMO-free', they will be able to emphasise the quality of Swiss produce," he said.

While the vote has a symbolic meaning, the moratorium will result in very little change from current practice.

However, the ban could isolate Switzerland within Europe and lead to a brain drain of researchers, its opponents said.

"This clear yes to a moratorium is a bad sign for Switzerland's image as a research centre," the youth wing of the centrist Free Democrat Party said in a statement.

CLEAR WIN

Official results showed that 55.7 percent of voters accepted the proposal to impose a five-year moratorium.

All 26 cantons also accepted the ban, which which will give Switzerland a tougher regime on GMOs than its neighbours in the 25-nation European Union.

In the EU, restrictions apply only to specific crops and are temporary in nature, rather than the blanket ban proposed by the Swiss.

While Switzerland is home to many pharmaceutical firms as well as agro-chemicals group Syngenta, only around 1 percent of the research performed in the alpine nation involves GMOs, Ammann noted.

Under the country's legislative system, the Swiss electorate is regularly asked to vote on major decisions.