The Dutch electoral commission says that an activist group has gathered enough signatures to force a non-binding referendum in the Netherlands on a European Union pact with Ukraine.

The electoral commission announced Wednesday that nearly 428,000 messages of support were collected by a group called GeenPeil seeking a referendum, easily surpassing the 300,000 threshold necessary under a law that came into force this year.

Organizers of the petition call the EU pact with Ukraine a symbol of an expansionist mindset that prevails in the 28-nation bloc.

The move is the latest manifestation of Dutch skepticism toward Europe. The Netherlands is a founding EU member but rejected an EU constitution in a 2005 referendum.

No date was immediately set for the vote, which must be held within six months.