Top British clubs have been told to stop linking to betting websites from their social media channels because of the potential harm it could cause.
A group of 50 former addicts and others affected by gambling have written to 11 teams in the Premier League, EFL and Scottish Premiership.
They highlight how clubs offer match odds and links to betting sites when revealing starting line-ups on Twitter.
The adverts have also drawn criticism from some football supporters.
The letter, which has support from parliamentarians and leading clinicians, says the group is "distressed" to see this type of advertising, which is "difficult for those of us who are addicted or in recovery".