NEW YORK - The scandal-hit liberal grass-roots group ACORN sued the U.S. government on Thursday, saying it did not have the right to cut off ACORN's federal funding because the group had not been convicted of a crime.

The U.S. Congress voted in September to cut off federal money to the Association of Community Organizations for Reform Now (ACORN), after conservative activists secretly filmed employees in several cities giving tax and housing advice to a couple posing as a pimp and a prostitute.

It's not the job of Congress to be the judge, jury, and executioner, said Jules Lobel, an attorney with the Center for Constitutional Rights, which brought the case in Brooklyn federal court.

We have due process in this country, and our constitution forbids lawmakers from singling out a person or group for punishment without a fair investigation and trial, Lobel said.

Republicans have long accused the group of fraud in registering voters and improperly mixing political and nonpolitical activities. They say it has received $53 million in federal money since 1994.

ACORN, which has also suffered an embezzlement scandal involving the founder's brother, has separately sued the makers of the videos.

The lawsuit seeks a temporary restraining to prevent the Congress from reallocating funds designated for ACORN.

Beyond its voter registration drive, the group promotes affordable housing programs for lower-income people, offers tax counseling and has aggressively fought home foreclosures.

(Reporting by Edith Honan; Editing by Vicki Allen)