Professional footballers in England and Scotland have been invited to support a campaign addressing homophobia in the game by wearing rainbow laces in their boots next weekend.
Sets of laces have been sent to all Premier League and Football League clubs, plus the 42 teams in the Scottish Professional Football League by gay rights charity Stonewall, who are being backed by bookmaker Paddy Power.
The Right Behind Gay Footballers campaign is focused on changing attitudes in football rather than urging players to come out and wants players to wear the laces in games on September 21 and 22.
Stonewall deputy chief executive Laura Doughty said: "It's time for football clubs and players to step up and make a visible stand against homophobia in our national game."
Doughty added: "By wearing rainbow laces players will send a message of support to gay players and can begin to drag football into the 21st century."
There are no known openly gay footballers in the English and Scottish professional leagues.
Former Leeds and United States winger Robbie Rogers retired in February, announcing his sexuality and claiming he could not have continued his career due to the "pack mentality" that changes the way footballers behave.
He later reversed his decision to quit the game and signed for the LA Galaxy.
Before Rogers' revelation, only two footballers had publicly said they were gay.
Former England Under-21 international Justin Fashanu was the first professional footballer in Britain to come out, in 1990, before he took his own life eight years later, aged 37.
Swedish lower league player Anton Hysen - son of former Liverpool defender Glenn Hysen - also came out in an interview with a Swedish football magazine in 2011.