Elite female soccer players are threatening to sue FIFA over a plan to use artificial turf -- rather than natural grass -- at next year’s Women’s World Cup tournament, saying such a move amounts to gender discrimination.

Women athletes, who will be travelling from Europe, North America and Asia to compete in several Canadian cities for the month-long summer tournament starting in June 2015 say they expect to play on natural grass fields, and that forcing them to play on artificial turf violates the law under Canada’s Charter of Rights and Freedoms.

During the recent World Cup held in Brazil, the men played only on a surface made of natural grass, as per regulation. Proponents of a natural grass playing field say it reduces injury and the surface better interacts with the soccer ball.

In a July 28 letter by legal counsel to the Canadian Soccer Association and FIFA, the group of athletes crying foul called on tournament organizers to correct the “mistake.”

“Proposing that world-class female athletes be singled out to play on a second-class surface is wrong and should be unacceptable to your organizations, your broadcast partners, and your corporate sponsors,” the letter said.

The letter threatening legal action was written on behalf of a group of high-profile players, including Americans Abby Wambach and Alex Morgan, and Germany's Nadine Angerer.

Catherine Gleason-Mercier, one of the lawyers representing the women athletes, says her clients want to play on the “best surface possible” for their sport’s highest tournament.

“It’s good for women’s sport, it’s good for viewers of the game, it’s good for people sitting at home watching,” Gleason-Mercier told CTV Montreal. “This is a win-win for everybody if the tournament is played on grass.”

But some say the decision has less to do with sex or gender than it does Canada’s cooler climate. Nearly all of the country’s major stadiums are indoors due to the colder weather in the winter months.

Eric Leroy, technical director for the Quebec Soccer Association, wonders why Canada was even chosen as the host country for next year’s tournament.

“If you decide to compete in Canada, of course, you have to decide to play on artificial turf because the majority of the big stadiums in Canada … are on artificial turf,” LeRoy told CTV Montreal. “Probably we are the only country in the world where we play inside on an artificial field.”

But that explanation not good enough for the athletes, who say artificial turf is “wholly unjustified as a financial imperative.”

“The installation of natural grass would cost but a fraction of your organization’s budgets thus defeating any defense of undue hardship,” the letter stated.

The athletes had requested a response from the two organizations by Aug. 4. An Aug. 5 article in The Equalizer, a publication devoted to women’s professional soccer, stated that both FIFA and Canada Soccer spokespeople had confirmed to them receipt of the letter, but declined to comment any further.

The 2015 FIFA Women’s World Cup runs next year from June 6 to July 5.

With a report by CTV Montreal’s Max Harrold