Five major cast members of the hit CBS show The Big Bang Theory are still negotiating their contracts and, as a result, production on Season Eight of the show has been forced to shut down temporarily.

Stars Jim Parsons, Johnny Galecki, Kaley Cuoco, Simon Hedberg, and Kunal Nayyar are all waiting to reach deals with Warner Bros Television and have decided not to return to work until the matter has been fully resolved.

The first table read of the new season was set to take place Tuesday morning but was canceled.

“Due to ongoing contract negotiations, production on The Big Bang Theory — which was originally scheduled to begin today — has been postponed,” said a statement from WBTV.

The cast members are negotiating in groups, with Parsons, an Emmy winner for his role as Sheldon, Galecki, and Cuoco seeking salary increases from their reported $325,000 per episode to $1 million per episode in addition to back-end participation. Those numbers would rival the salaries of all six cast members of Friends when that series ended in 2004.

Hedberg and Nayyar are also reworking their deals together, looking to secure large raises commensurate with those of co-stars Mayim Bialik and Melissa Rauch when they signed their new deals with the studio.

The production delay comes as somewhat of a surprise to Warner Bros Television and head of CBS, Nina Tassier, who seemed unconcerned about the potential standoff at this year’s Television Critics Association Summer Press Tour. “We’re feeling very confident that everything will work out,” she told reporters. “These deals manage to get done miraculously somehow year after year.”

But it’s evident that everything has not been worked out and this puts the studio and the network at a disadvantage. WBTV was convinced the cast would resume work with or without closed deals and CBS has announced their renewal of the hit comedy through Season Ten. This gives all five stars considerable leverage in getting the salaries they feel they deserve.

The Big Bang Theory is the number one comedy on network television at the moment and a crucial component of CBS’ upcoming fall season. The half-hour sitcom is also a big winner in syndication for TBS, with repeats of the show consistently gaining better ratings than original programming on all four major networks.