The Big Bang Theory may be about to lose its biggest star.

The Big Bang Theory may be in trouble as the show enters its 10th season, as bosses try to renew the contracts of the sitcom’s biggest star’s.

The current contracts are set to expire at the next season – meaning the cast could chose to depart or the show could carry on without them.

To make matters more complicated, the cast’s leading stars – including Jim Parson, Johnny Galecki and Kaley Cuoco – are seeking a pay rise before agreeing to continue.

The show’s boss, Steve Molaro, has discussed whether the show could survive without its biggest stars.

“I have no idea. I think it would certainly be different and weird. There’s no point in me wondering what it could be when I have 19 scripts staring down at me that need to get written,” he told The Hollywood Reporter.

“All we can do right now is focus on season 10 and go script by script, which is what we would be doing anyway,” he added.

“As far as I’m concerned, here in the writers’ room, it’s business as usual: moving forward with the characters and letting them live their lives day by day and feeling out what happens with them.”

Parsons recently said not hiding his sexuality when he became famous the ‘only logical’ option he had.

The actor says he never felt brave for being openly gay while growing up in Texas.

Since joining the show, the star has since become one of the most powerful actors in Hollywood.

Last year, Forbes reported that his pay is now so high that he earns more than any other actor in television.

His reported $29 million earnings surged after the cast signed a new deal to continue making the show – surpassing 2014’s list-topper Ashton Kutcher.