WASHINGTON (AP) _ The government on Tuesday told a judge he should force Chrysler Corp. to recall 91,000 Cirrus and Stratus cars because their seat belt systems are unsafe.

Last year, a nut anchoring the seat belt of a 1995 Cirrus pulled out of the floor during a routine government test, leaving a hole in the floorboard.

The government wants the 1995 Cirrus and 1995 Dodge Stratus, which has the same anchoring system, recalled and fixed for free because the car failed the federal strength test for seat belt anchors.

Chrysler is the only company ever to fight a recall in court because a car failed a government safety test standard. The company says the cars are safe but the test was unfair because regulators were not clear about its specifications so companies could duplicate it.

``At least give the industry notice in advance so they know what is required,'' Erika Jones, the lead counsel for Chrysler, told U.S. District Court Judge Emmet G. Sullivan.

Margaret Hewing, the government's lead counsel, said the cars are unsafe and should be recalled. The National Highway Traffic Safety Administration was clear about the range of the test's requirements, she said.

``NHTSA's position is reasonable. It is consistent,'' Hewing argued.

Chrysler lawyer Lewis Goldfarb believes the court battle has implications for all automakers that must pass the test. If the standard is not rewritten, Goldfarb said, ``it will give less guidance to the industry as to what they might do to comply, so you'll see a lot of confusion out there.''

Chrysler officials say the court case is not about safety because the vehicles' anchor system has been adequately tested and has not failed in any real-world crash.

NHTSA officials have said they are particularly sensitive about enforcing seat belt quality because seat belts are the main safety devices that protect motorists in crashes.

The government's anchor standard has been in effect for more than 25 years and, during that time, has been violated 54 times. In every case, until Chrysler refused this year, the car company recalled the vehicles to strengthen the belt anchor.

``We have a crash test that we've established and Chrysler failed it,'' NHTSA spokesman Phil Frame said Tuesday. ``The test was well established and we believe they had adequate notice of the test we run on this.''

Sullivan is likely to rule within a few months on whether the government reasonably interpreted the standard and whether Chrysler had notice of it.

The same anchor system was used in all Cirrus and Dodge Stratus cars built between June 30, 1994, and May 15, 1995. After that, Chrysler replaced the weld-nut anchor with a stronger design that includes a metal plate.