The US Supreme Court has been hearing evidence on whether the largest sex discrimination lawsuit in American history should go ahead.
A group of women is suing the world's biggest retailer, Wal-Mart, claiming they were held back because of their gender.
They want to bring a class action suit on behalf of more than a million women.
Wal-Mart denies the allegations and says it promotes women employees and pays them well.
The group bringing the lawsuit says Wal-Mart systematically discriminated against women in stores across America.
But lawyer Theodore Boutrous Jr, for Wal-Mart, said on Tuesday the class action nature of the legal action deprived the company of legal rights as it was forced to defend the treatment of women regardless of the jobs they held or their place in the Wal-Mart chain.
This is the first step in what those bringing the case hope could become a landmark legal moment. What started out as a grievance over pay and promotion among a handful of women could turn into the largest sex discrimination lawsuit in America.
The first claims of women being passed up for promotion at Walmart stores surfaced 11 years ago, but the six women pursuing this case do not want their grievances to be heard separately.
Instead, they are pushing for the case to be heard as a class action - to include all female store employees since 1998 - because they claim there is a wider culture of sex discrimination in the company. It is up to America's highest court to decide whether this is how the case should proceed.
Walmart denies the charges, but if a class action goes ahead, the company faces the prospect of a billion-dollar payout, as well as a dent to its reputation.
"There is absolutely no way there can be a fair process here," Mr Boutrous said.
Justice Ruth Bader Ginsburg said the issue at stake at this early stage in the process was not proving discrimination, but showing enough evidence to go forward.
"We're talking about getting a foot in the door," Justice Ginsburg said.
http://www.bbc.co.uk/news/world-us-canada-12888425
