Downing Street has defended Rishi Sunak after a video emerged of the prime minister seemingly making a joke that mocked transgender people, saying the comments were simply aimed at a political opponent. The footage of Sunak addressing fellow Conservative MPs, leaked to PinkNews, shows him making fun of Ed Davey after the Liberal Democrat leader said it was possible for a woman to have a penis, which can happen under the government’s own gender recognition laws. Addressing the 1922 Committee of backbench Tories on 5 June, the footage, seemingly shot on a phone held surreptitiously towards the floor, has Sunak’s voice saying Davey “has been very busy”. Sunak went on: “Like me, you can probably see that he was trying to convince everybody that women clearly had penises. You’ll all know that I’m a big fan of everybody studying maths to 18, but it turns out that we need to focus on biology.” The comment was greeted by laughter in the room. While Sunak’s government is opposed to self-recognition for transgender people, as sought by the Scottish government, people are allowed to apply for a gender recognition certificate, changing their gender under law, even if they have not had gender-affirming surgery or treatments, or do not plan to. An unnamed Conservative MP quoted by PinkNews said: “It is profoundly depressing – this whole ‘othering’ of minorities – pretty much any minority. Without stopping to think we have equalities legislation for a reason, to stop discrimination against anyone with a protected characteristic – we should be trying to understand and support, not belittle and demonise.” Sunak’s spokesperson said the target of the joke had been Davey, and the general tone of the comments was not different to remarks the prime minister had made before. “You’ve heard the prime minister talk about his enormous compassionate understanding for people questioning their identity and that they should be treated with dignity and respect,” the spokesperson said. “On this specific issue, these are points he’s made in interviews, publicly … My understanding is that this was a joke aimed at a political opponent rather than a specific group.” Asked if Sunak would use any other minority group as the punchline for a joke, the spokesperson said: “I don’t agree with that characterisation. I think, again, he was making a point about a political opponent and their views.” Sunak previously has made transgender rights a divisive culture war issue, regularly using a section of his speeches during last summer’s Conservative leadership campaign to say he would stand up for “our women”. The government is due to announce updated guidance for how teachers should deal with transgender issues in schools, expected to say that they are obliged to inform parents if a child is questioning their gender. Some teachers have said this could leave students at risk of harm or homelessness.