Argentina's government has given its leading critic a Dec. 7 deadline to sell off most of its broadcast stations.

In a lengthy TV spot airing during Saturday's much-watched football games, the government announced that it will immediately put Grupo Clarin's cable TV stations up for public auction on that date to comply with media industry regulations approved in Congress three years ago. That law seeks to break up media monopolies by limiting how many broadcast stations one company can own.

The spot accuses Clarin of operating illegally by refusing to sell off most of its 240 cable systems, 10 radio stations and four TV channels.

Clarin says the law is unconstitutional and that even if its injunction runs out on Dec. 7, it should have another year to divest.