Members of a Swiss pro-neutrality grouping have called on Switzerland to abandon plans for closer cooperation with the European Union.
At an assembly meeting of the Campaign for an Independent and Neutral Switzerland (CINS) in the Swiss capital, Bern, on Saturday, around 1000 members unanimously approved a resolution calling on the Swiss government not to sign up to the Schengen agreement.
The accord, which has been signed by a majority of EU member states, abolishes border controls between its signatories. It also provides for common policies to fight crime, as well as a shared system of investigation and information.
The issue of Switzerland's signing up to Schengen is one element of ongoing negotiations between Brussels and Bern on a second series of bilateral accords.
A first series of Swiss-EU accords, which cover issues such as cross-border trade and transport, is due to come into effect on June 1.
Rejection of Schengen
But in a press communiqué released at the end of Saturday's meeting, CINS said Switzerland's adhesion to Schengen would represent a "step towards integration with the EU and is therefore to be wholeheartedly rejected".
The resolution adopted by CINS members also warns that Swiss participation in Schengen - so named after the town in Luxembourg where the first agreements on a territory without borders were signed - would damage the country's "freedom, sovereignty and neutrality".
The Swiss government has previously endorsed signing up to the accord, claiming it is in the best interests of Switzerland and its internal security.
Christoph Blocher, the right-wing populist member of the Swiss People's Party, also used the occasion of Saturday's assembly meeting to call on CINS members to rally against any future attempts by the Swiss government to accede to the EU.
swissinfo with agencies