A group of elite players has filed a lawsuit in Canada challenging plans to play the 2015 Women’s World Cup on artificial turf.

The players, led by U.S. women’s national team forward Abby Wambach, filed Wednesday in the Ontario Human Rights Tribunal in Toronto, attorney Hampton Dellinger told The Associated Press.

The women claim that playing the sport’s premier tournament on fake grass amounts to gender discrimination under Canadian law. Their male counterparts have always played the World Cup on natural grass surfaces, and will for the foreseeable future.

The players say they believe there is a greater risk of injury on turf and that an artificial surface impacts both how the game is played and how the ball behaves.

Among the athletes joining Wambach are U.S. teammate Alex Morgan, Germany’s Nadine Angerer, Brazil’s Fabiana Da Silva Simoes and Spain’s Veronica Boquete.

“The gifted athletes we represent are determined not to have the sport they love be belittled on their watch. Getting an equal playing field at the World Cup is a fight female players should not have to wage but one from which they do not shrink. In the end, we trust that fairness and equality will prevail over sexism and stubbornness,” Dellinger said in a statement.

On Tuesday, a FIFA official visiting Canada in advance of the tournament next year said there were no plans to reconsider using artificial turf.

“We play on artificial turf and there’s no Plan B,” said Tatjana Haenni, FIFA’s head of women’s competitions.

FIFA has appointed an independent examiner to make sure the turf at the six venues meets its strict guidelines for top-tier tournaments. The consultant is traveling with a FIFA delegation currently inspecting the sites.

FIFA rules stipulate that matches can be played on artificial turf if special dispensation is granted, as it was in Canada’s case. The regulations also state that all matches in a tournament must be played on the same surface.

Canada’s bid for the event specified that the final match be played at Vancouver’s BC Place, which seats 55,000 and has an artificial turf.

But many players, including Wambach, have been voicing their objections since the bid was accepted. They sent a letter to FIFA and the CSA in July, saying they were prepared to take the legal action.

Since then, there has been growing support for the women on social media, with celebrities including actor Tom Hanks and NBA player Kobe Bryant joining the cause. Tim Howard, the goalkeeper for the U.S. men’s team, also voiced his support on Twitter.

“There’s so many different debates around this. But the reality is, the men would never play (the World Cup) on field turf,” Wambach told the AP. “So for me it’s a women’s rights issue, it’s an equality issue.”

The players have said they will not boycott the World Cup matches, which will be played in six Canadian cities.

Many players believe that FIFA and the Canadian federation could cover the six fields that will be used with sod. The real stuff was rolled onto the artificial surface at Michigan’s Big House this summer for a match between Manchester United and Real Madrid.

It’s not ideal, they say, but better than the alternative.

“Is it going to cost them a little bit of money? Yeah. Maybe a drop in the bucket for FIFA for the amount of money that they have,” U.S. player Megan Rapinoe said last month. “It just seems like they’re kind of like, ‘Oh, yeah, whatever, this is just what you’re going to have.’ When there’s an alternative option, that’s frustrating.”

Wednesday’s legal action, known as an application, names the Canadian Soccer Association and FIFA. Attorneys filed a brief detailing the facts and law in support of the discrimination claim, and also filed a motion to expedite the proceedings.

The U.S. women’s team is about to take part in the championships for soccer’s North and Central American and Caribbean region, which serves as qualifying for the World Cup next year. The tournament will be played in four U.S. cities starting on Oct. 15 with the final scheduled for Oct. 26 at PPL Park in Pennsylvania.