California lawmakers and Gov. Arnold Schwarzenegger are still trying to strike a deal on the state's budget gap.
But if there is no deal by Friday, state government workers will take their first furlough day.
Labor representatives said they intend to appeal Sacramento County Superior Court Judge Patrick Marlette's ruling last week confirming that the governor has authority to reduce work hours during a fiscal emergency.
Unions are also negotiating with the state to find an alternative to Schwarzenegger's order shutting down state government on the first and third Friday of each month.
Schwarzenegger has declared a fiscal emergency. California faces a $42 billion budget deficit through June 2010.