The cast of Modern Family has declared war on producer 20th Century Fox Television.

Sources tell The Hollywood Reporter that cast members Ty Burrell, Julie Bowen, Jesse Tyler Ferguson, Eric Stonestreet and Sofia Vergara are filing suit today in Los Angeles Superior Court to void their contracts. The legal theory, according to sources who have seen the lawsuit, is that their deals violate California's "7 Year Rule," which prohibits personal services contracts for longer than 7 years. This tactic is a common one for actors who seek to void contracts during renegotiations for increased compensation.

Read the full complaint HERE.

The move comes amid a salary standoff that has already delayed today's scheduled table read that would have marked the start of the fourth season of Modern Family, one of TV's top-rated comedies. The cast, minus Ed O'Neill, who is paid more than his co-stars and is negotiating separately, has hired litigator Jeff McFarland with LA's Quinn Emanuel firm and are pressing their case in court.

UPDATE: A source close to the negotiations tells THR that O'Neill has decided to join his castmembers as a plaintiff in the lawsuit. O'Neill has his own salary beef with 20th TV but he is paid on a different track and was thus not involved in the original plans to sue. Yet O'Neill is said to want to join the suit out of solidarity with his cast, and once he is officially signed as a client by litigator McFarland, the suit will be amended to add O'Neill, according to sources.

EXCLUSIVE: 'Modern Family' Cast Still Without New Contracts as Tuesday Table Read Nears

The six adult cast members currently have contracts through the seventh season of the show. But as THR previously reported, renegotiations are common between the third and fourth seasons, when casts of hit shows typically get bigger paychecks in exchange for agreeing to continue with the show beyond the seventh season. Sources tell THR the five cast members are being offered salary increases as follows: $150,000 per episode plus a $50,000 per episode bonus for season 4; $200,000 per episode for season 5; $225,000 for season 6; and up to $325,000 for an anticipated season 9. The cast is asking for much more, including more than double the offered salary if the show goes 8 or 9 seasons, as expected.

A rep for 20th TV declined to comment.

With the exception of O’Neill (Married… with Children), the actors were paid in the $65,000-an-episode range for the show’s 22-episode third season, according to sources. O’Neill is believed to have made in the $105,000 range this past year.

The series is a profit center for both the studio and the network, regularly drawing 13.1 million viewers, according to Nielsen. In 2011, Modern Family generated $164 million in advertising revenue for ABC, up 40 percent from a year earlier, reports Kantar Media. What’s more, the multiple Emmy-winning series has proved an American Idol-style launching pad for the network’s other comedies, including Happy Endings, Don’t Trust the B---- in Apartment 23 and the upcoming alien effort The Neighbors.

Coming out of the show's breakout freshman season in 2010, 20th TV inked a rich syndication deal with USA – the NBCUniversal-owned cable network’s first major comedy acquisition—for a license fee close to $1.5 million an episode, say sources. That’s roughly on par with the deal Turner’s TBS struck with Warner Bros. TV for repeats of The Big Bang Theory. Modern Family is poised to reap many more millions from broadcast stations when the series rolls out in syndication in 2013, and foreign revenue is said to be particularly robust.

McFarland is a fitting choice of lawyer to represent this group. The Quinn Emanuel partner has a lot of experience with "7 Year Rule" cases, having won agent Ed Limato's 2007 lawsuit against the ICM talent agency. No word yet on which lawyer 20th TV will hire to represent it in this case.

E-mail: Matthew.Belloni@thr.com

Twitter: @THRMattBelloni