The United States has just marked National Girls and Women in Sports Day, writes columnist Andy Winter. Its purpose is to break the sex stereotypes built around the sports industry to assert that women belong in every aspect of sport.

Regular readers will know of my support and enthusiasm for Lewes Football Club. I was so inspired by the club’s equality agenda that, along with over 2,500 others in more than 40 countries, I became a co-owner. Lewes FC was the first and remains the only professional or semi-professional football club in the world to have equality between their men and women’s teams: equal playing budgets, access to facilities, marketing budgets, and so on. This is what has been called #EqualityFC.

This approach just seems fair. Advancement of women’s sport is happening in England thanks to football’s Lionesses, rugby’s Red Roses and the women’s cricket team, to mention but a few. In individual sports there have been some exceptional women athletes such as Denise Lewis, Jessica Ennis-Hill, and Brighton’s Sally Gunnell.

The former swimmer Sharron Davies, in her excellent book Unfair Play, catalogues the systematic doping of swimmers from the former East Germany. Because of their drug-fuelled enhanced performance Sharron was denied a gold medal in the 1980 Moscow Olympics. She lists others who were denied medals and thus the life opportunities and financial rewards that would have followed Olympic success.

There is widespread acceptance that the East Germans cheated their way to swimming success. Some of their gold medallists have offered to return their medals so that clean athletes could receive them and get the belated recognition that they deserve. Yet the Olympic authorities have failed to act. Sharron says it is too late for some British swimmers like Ann Osgerby, June Croft and Jackie Wilmott who have all sadly passed on.

It is fairness which makes me opposed to the inclusion of trans women (those born male) in women’s sport. Women have fought long and hard to get their sport recognised, in media coverage and in rewards. But if trans women had been allowed to compete against Lewis, Ennis-Hill and Gunnell, they almost certainly would not have secured their Olympic gold medals.

Men and women’s sport is different because men and women have different physiologies. The former Olympic swimmer, Nancy Hogshead-Makar has compared the physiologies and performances of the US swimmers Missy Franklin and Ryan Lockte. Both are multiple Olympic and world champions. Both have had first-class training, coaching and support. Both are 6ft 2in with 6ft 4in “wing spans”. Both hold world records in 200 metre backstroke. Ryan’s best time is 1:52:96 while Missy’s world record is 2:04:06. Missy’s best would have placed her 50th in the US men’s Olympic trials. This is similar in track and field, and in other sports.

When trans women who have been through male puberty are allowed to compete in women’s sport, in an echo of East German swimmers, they have an unfair advantage that is likely to rob women of their success, recognition and financial reward. And in contact sports it can be dangerous. For example, a male of equal weight and height to a female can punch 160 per cent harder. If a 6ft 6in trans woman was allowed to play rugby, even against the top women rugby players like Marlie Packer and Abby Dow, the risk of injury would be great. How long would it be before the wonderful Red Roses were dominated by players who have benefited from male puberty?

The developmental biologist Dr Emma Hilton and Dr Tommy Lindberg, an exercise physiologist, concluded in a joint peer-reviewed research paper: “The biological advantage, most notably in terms of muscle mass and strength, conferred by male puberty and thus enjoyed by most transgender women is only minimally reduced when testosterone is suppressed by current sporting guidelines for transgender athletes.”

Hilton and Lindberg reported that even after a year’s hormone-reduction therapy, the expected five per cent drop in muscle mass in trans women resulted in a negligible loss of muscle strength and they remain much stronger than any of the women they wish to compete against.

For these and other reasons, I cannot support trans women competing in women’s s port. There is an alternative, a third category in which trans women can compete against each other. However, it is notable that where this has been trialled, the event has been cancelled due to a lack of entrants. It is also notable that trans men (those born female) have never sought to compete in men’s sport where they would have a huge physiological disadvantage.

This is not about prejudice. It’s simply about fairness.

Andy Winter is a former councillor who worked in social care and homelessness services for 40 years