Washington ? A former tire plant worker’s complaint that she was paid thousands of dollars less than men in the same job made it to the Supreme Court Monday in a case that could affect pay discrimination claims nationwide.

The justices engaged in a lively but inconclusive debate over how to apply a 180-day deadline for complaining about discriminatory pay decisions under Title VII of the federal Civil Rights Act of 1964.

Lilly Ledbetter sued Goodyear Tire & Rubber Co., claiming that after 19 years at the company’s Gadsden, Ala., plant, she was making $6,000 a year less than the lowest-paid man in the same job.

Ledbetter claimed the disparity existed for years and was primarily a result of her gender. A jury agreed, but an appeals court overturned the verdict.

Enforce the statute of limitations strictly and an employee is “condemned to perpetually unequal pay for equal work unless she recognizes and complains about the discrimination within a few short months after it first begins,” Kevin Russell, Ledbetter’s lawyer, argued to the court.

Each smaller paycheck should be treated as a new act of discrimination, Russell said.

Allow employees to reach back years to claim discrimination and the deadlines mean nothing, lawyers for Goodyear and the Bush administration said.

“No one at Goodyear took Miss Ledbetter’s sex into account during the charge-filing period in deciding what to pay her,” said Glen Nager, Goodyear’s attorney.

Applying the 180-day deadline to decisions made years ago makes no sense in a situation in which the disparity grew over time, Justice Ruth Bader Ginsburg said.

Early on, “there is no reason to think there is going to be this inequality,” she argued.

But Chief Justice John Roberts was skeptical that employees should be allowed to challenge decisions made years ago. “It could be 40 years, right, that there was a discriminatory act, in one of the semiannual pay reviews I was denied…a raise that I should have gotten,” Roberts said.

Only Justice Clarence Thomas, who rarely speaks up during court sessions, did not participate in the questioning. But he could play a pivotal role in deciding the case.

In the 1980s, Thomas was chairman of the Equal Employment Opportunity Commission, which is responsible for investigating workplace discrimination claims.

One of the court’s most conservative justices, Thomas was joined by his four liberal colleagues in a 5-4 decision in 2002 that made it easier for victims to complain about long-term job discrimination or harassment when shabby treatment is extended over a period of months or years.

Goodyear denied discriminating against Ledbetter. She received periodic raises despite being ranked near the bottom of her group of workers, the company said.