BRUSSELS — More than one million signatures have been gathered in a legal bid to “freeze” genetically modified (GM) crop cultivation in the European Union.

Environmental campaigners Greenpeace and Avaaz announced that the target for their online petition had been met. They are seeking to use a new citizen charter created under the European Union’s Lisbon Treaty to put authorizations on hold.

A Brussels official said Wednesday the complaint would be passed to “political” advisers. However, the leading expert on the European parliament committee handling questions surrounding GM farming, German Green lawmaker Gerald Hafner, said there could be a legal challenge.

Under Lisbon, if a million citizens from a broad base of E.U. countries lend their names to moves to change the law, the European Commission, the bloc’s day-to-day executive, is obliged to consider the grievance. The idea was to bring Europe closer to the people.