A coalition of Ontario unions that has spent millions on attack ads targeting Progressive Conservatives during past election campaigns is fighting a Liberal law that limits how much third parties can spend on election advertising.
The Working Families group has filed a constitutional challenge against Bill 2, alleging the law that took effect last year infriges on its rights to free expression and free association.
The group says the law effectively restricts how organizations and individuals can participate in the election process.
Under the law, both political parties and the special interest groups known as third parties have caps on how much they can spend on political advertising during election campaigns and in the six months leading up to them.
It's the first time third parties, who have exerted considerable influence in past elections, have spending limits.
A spokesman for the Ministry of the Attorney General says the government believes the rules comply with the Charter of Rights and Freedoms.