The Amsterdam branch of animal rights party PvdD wants the city to ban mass balloon releases, saying the deflated balloons are a danger to animals.

Even though some types of balloons are biodegradable, ‘releasing balloons is the same as throwing rubbish on the street and that is not allowed either,’ says local councillor Johnas van Lammeren.

Researchers at Wageningen University say that orange balloons released on King’s Day last year ended up in a nature reserve in Normandy, the Telegraaf reports on Tuesday.

Last year, the release of 150,000 helium balloons to celebrate Willem-Alexander becoming king was halted because of concerns about the impact on the environment.