The issue over weekend penalty rates is set to be a major political fight from now until the next federal election. The Federal Opposition says it will try to challenge the Fair Work Commission's ruling. Speaking with AM's Sabra Lane, shadow attorney-general Mark Dreyfus says that, despite being set up by the Rudd Labor government as an 'arm's-length' body to arbitrate independently, the rules that have been set for the commission need to be changed and that Labor will use legislation or some other parliamentary solution to change the system.