Lawyers representing 40 top women's soccer players challenged FIFA and the Canadian Soccer Association (CSA) on Friday by saying they would file a lawsuit against them over staging next year's women's World Cup in Canada on artificial turf.
Players from Germany, Brazil, Spain and the United States are among those claiming that the use of artificial turf instead of grass for the June 5-July 6 event is discriminatory, given the men's World Cup is always played on grass.
Their lawyers had given FIFA a Friday deadline to open discussion or face an imminent lawsuit in a Canadian court.
Since such no discussion had begun, the players' attorneys said they would be focused on finalizing and filing the necessary legal papers.
"A lawsuit is a last resort but one that unfortunately appears necessary and will be initiated in coming days," attorney Hampton Dellinger, the Washington based law firm representing the players, said in a statement.
"As the already drafted legal papers demonstrate, the players and their attorneys are prepared to put before a judge what we believe is a clear -- and very unfortunate -- case of gender discrimination."
Abby Wambach of the United States and Germany's Nadine Angerer, FIFA players of the year for 2012 and 2013, respectively, are among those who signed the original letter.
The 2014 FIFA World Cup for men in Brazil was played on grass and there are no plans to shift future men's tournaments to artificial turf.
"The discriminatory proposal of FIFA and the Canadian Soccer Association to stage the 2015 women's World Cup on artificial turf, coupled with their refusal to discuss ways to fix the mistake, have left the players with no choice," said Dellinger.
"It is now time to ask the courts to stop FIFA and CSA from forcing elite athletes to compete under game-changing, dangerous and demeaning conditions. ...
"World class games cannot take place on second class surfaces."
The World Cup will be staged in six cities: Vancouver, Edmonton, Winnipeg, Ottawa, Montreal and Moncton, where stadiums with artificial turf predominate.
