A campaign group is urging parkrun to prevent transgender women from registering in the female category, arguing that competitors born male may have physical advantages and that the policy is unfair to women and girls. The dispute matters because parkrun is a large nationwide community event, while prominent athletes and campaigners are also threatening legal action over its eligibility rules.

Reality Rules Runners UK is launching a mass sign-up campaign through participants’ parkrun profiles, and says it wants to demonstrate support for sex-based categories. Olympic swimmer Sharron Davies, yachtswoman Tracy Edwards and the Women’s Sport Union have reportedly given parkrun until next Friday to change its policy; former marathon runner Mara Yamauchi says transgender women hold 20 female local parkrun records, including two course records. The article says parkrun has more than 1,400 UK events and links the campaigners’ argument to a recent Supreme Court ruling on the legal meaning of sex.