Two Russian political parties have appealed to the Constitutional Court to rule on the legality of a recently adopted law mandating heavy fines for organizing or participating in unsanctioned demonstrations.

More than 100 lawmakers from the A Just Russia and Communist parties signed the appeal, which argues that the massive increase in fines and the introduction of mandatory public-service sentences for some violations are unconstitutional.

The bill was introduced and passed by the ruling United Russia party.

Activists have charged that the bill is intended to restrict the constitutional right of free assembly.