FOX News Channel is suing comedian Al Franken for using its signature phrase “fair and balanced” in the title of his new book.

The network wants a Manhattan court to order Franken to change the name of his soon-to-be-released book, “Lies and the Lying Liars Who Tell Them: A Fair and Balanced Look at the Right.”

The all-news network’s suit Franken’s humor “sophomoric” and a “not a well-respected voice in American politics; rather, he appears to be shrill and unstable.”

A spokeswoman for Dutton called the suit “un-American.”

“The attempt to keep the public from reading Franken’s message . . . runs contrary to everything this country stands for,” said spokeswoman Lisa Johnson.

Fox maintains their problem is a trademark issue, not a First Amendment one.

“FNC has used ‘Fair and Balanced’ as a primary slogan since the time of its launch in Oct. 7, 1996,” the suit says, adding FNC has trademarked the phrase and markets it.

The network, , like The Post, is owned by News Corp.

The suit isn’t the first clash between the network and Franken, a best-selling author of “Rush Limbaugh is a Big, Fat Idiot” who has made a name for himself poking fun at conservative targets.

The ex-“Saturday Night Live” cast member exchanged words with Fox News personalities at a press correspondents dinner in April 2003, the suit says.

Then, two months ago, Franken mixed it up with O’Reilly in a heated exchange at a booksellers’ luncheon in L.A. two months ago, where Franken called O’Reilly a “liar” and O’Reilly called Franken “an idiot.”

Both sides are due in court Friday.