Labour MP Charlotte Nichols has slammed criticism of American swimmer Lia Thomas as "lazy transphobia".
Last week Thomas became the first transgender athlete to win a US national college swimming championship with victory in the women's 500-yard freestyle.
Thomas, who swam for the University of Pennsylvania's men's team for three years before starting hormone replacement therapy in 2019, won the title in four minutes 33.24 seconds.
Her inclusion in the race has proved controversial, with some of her competitors criticising the decision to allow her to compete.
There were protests outside the venue at Georgia Tech on Friday, while Thomas was booed by some spectators while receiving her medal on the podium.
Former shadow minister for women and equalities Nichols has hit back at that criticism and congratulated Thomas on her achievements.
"As a former competitive swimmer myself, indeed, I know full well how much training is required for a title like this," Nichols tweeted.
"Anyone trying to diminish Lia Thomas' achievement because of lazy transphobia should frankly pipe down. Huge congratulations to her."
Former British Olympian Sharron Davies criticised Nichols' comments, replying: "Disgraceful abandonment of Women's right to equal opportunities in sport, so disappointing from an MP supposedly representing females too I presume? A total misunderstanding of elite sport.
"I seriously question your understanding of high-level performance competition/training."
Nichols' comments come after World Athletics president Sebastien Coe said women's sport faces a "fragile" future if sporting federations don't get the regulations right over the participation of transgender athletes.
Coe told The Times: "I think that the integrity of women's sport - if we don't get this right - and actually the future of women's sport, is very fragile."
Words by Rory O'Callaghan
Topics: Lia Thomas
Sport Casual