TLC, George Lange, File, Associated Press
FILE - In this publicity file image provided by TLC, Kody Brown, center, poses with his wives, from left, Robyn, Christine, Meri and Janelle in a promotional photo for the reality series, "Sister Wives." The polygamous family made famous on the TLC show is asking a U.S. judge not to block their challenge of Utah's bigamy law. Kody Brown and wives Meri, Janelle, Christine and Robyn filed a lawsuit in Salt Lake City's U.S. District Court in July 2011. The stars say the law is unconstitutional because it prohibits them from living together and criminalizes their private sexual relationships.

SALT LAKE CITY — A polygamous family made famous on a reality television show is asking a U.S. judge not to block their challenge of Utah's bigamy law.

Kody Brown and wives Meri, Janelle, Christine and Robyn filed a lawsuit in Salt Lake City's U.S. District Court in July.

The stars of the TLC show "Sister Wives" say the law is unconstitutional because it prohibits them from living together and criminalizes their private sexual relationships.

The Browns moved to Nevada in January after police launched a bigamy investigation.

No criminal charges have been filed.

State attorneys say the judge should dismiss the lawsuit. They say the Browns are not likely to be prosecuted.

Oral arguments in the case are set for Friday.