Britain’s main Opposition leader sparked a political furore and faced calls to apologise on Wednesday after he was accused of calling Prime Minister Theresa May a “stupid woman” in the House of Commons.

Labour Party leader Jeremy Corbyn was caught on camera appearing to mutter the insult during the Prime Minister’s weekly question-and-answer session.

The always-lively session was even more heated than usual, as lawmakers’ frustrations and divisions over Brexit boiled over into raucous shouting and personal jibes.

Mr. Corbyn’s spokesman insisted the Labour leader had said “stupid people” in reference to lawmakers on the governing Conservative side of Parliament. But the episode caused an uproar, with Conservative legislators yelling “shame” and “disgraceful”.

Commons Speaker John Bercow said he had not seen the exchange in question, but would look at the evidence and report back to the House later in the day.

The incident came as Britain’s Parliament attempts to end bullying, abuse and sexual harassment. Earlier this year a cross-party working group reported that one in five parliamentary workers had experienced or witnessed sexual harassment in the previous year.

It’s not the first time a male political leader has been accused of using sexist language. In 2011, then-Prime Minister David Cameron was accused of sexism when he adopted a catchphrase from a popular commercial and told a female lawmaker to “calm down, dear”.

Wednesday’s incident also has echoes of Donald Trump branding Hillary Clinton a “nasty woman” during the 2016 U.S. presidential campaign.