Fox News Channel’s No. 1 primetime lineup could be in jeopardy if network boss Roger Ailes gets booted.

Bill O’Reilly, Sean Hannity and Greta Van Susteren all might exit the network if parent company 21st Century Fox gets rid of Ailes in the wake of a sexual harassment lawsuit filed by former host Gretchen Carlson, according to a person familiar with the situation.

The three hosts have all spoken out publicly in defense of Ailes, who has been under internal investigation since shortly after the Carlson suit was filed. New York magazine reports that Ailes has until August 1 to step down or be fired.

O’Reilly, Hannity and Van Susteren have contract clauses that would allow them to depart if Ailes leaves the network, according to a Financial Times report, which cites two people briefed on the situation.

The high stakes showcase an escalating battle between Ailes and 21st Century Fox.

Fox News declined to comment.

More to come…