Canada’s leading wireless service provider industry group has mounted the latest court challenge of Quebec’s controversial plan to block certain online gambling domains.

On Wednesday, the Canadian Wireless Telecommunications Association (CWTA) filed papers with Quebec Superior Court asking them to reject the IP-blocking provisions of the province’s Bill 74 omnibus legislation as unconstitutional.

In May, Quebec approved Bill 74, which allows the Loto-Quebec provincial gaming monopoly to submit a blacklist of online gambling sites that compete with its own Espacejeux.com site. While this list is reportedly still being finalized, local internet service providers who fail to comply with the blocking orders could face fines of up to $100k per incident.

Earlier this month, the Public Interest Advocacy Centre (PIAC), a non-profit consumer protection group, filed the first official court challenge of Bill 74, arguing that the law was an unconstitutional affront to the federal government’s authority over telecommunications issues.