Jeremy Corbyn appeared to say stupid woman towards Theresa May at Prime Minister’s Questions.
The Labour leader appeared to mouth the words at the end of their PMQs clash, where Mr Corbyn had accused Mrs May of dithering over her Brexit plan.
While audio of Mr Corbyn’s comment was not recorded on the House of Commons’ microphone system, he was in full view of TV cameras at the time.
Conservative Party chairman Brandon Lewis said on Twitter: Will jeremycorbyn apologise or clarify exactly what he was saying? Looks shocking on the film, unacceptable in any environment.
Mrs May replied: I think that everybody in this house, particularly in this 100th year anniversary of women getting the vote, should be aiming to encourage women to come in to this chamber and to stand in this chamber and should therefore use appropriate language in this chamber when they refer to female members.
Tory MPs later shouted disgraceful and shameful when ex-minister Patrick McLoughlin accused Mr Corbyn of saying the words.
Commons Speaker John Bercow said he did not see the alleged utterance, but that anyone who did breach rules should apologise.
This is not acceptable. Please would you deal with it, as you often do Mr Speaker, in a fair way, but also from the point of view of women in this house who are fed up over decades of being abused by men.
After a lengthy row John Bercow said it would be a courtesy if Corbyn was in the Commons chamber and I very much hope that he will be.
As tempers frayed in the Commons chamber, the situation spiralled out of control, with Tory MPs waving phones at the speaker in a bid to show him evidence of the moment in question.
Ms Soubry asked Bercow if he would act immediately if evidence could be shown to him within perhaps two minutes.
And Tory MP Mark Francois urged the speaker to consult the video referee adding: The video evidence is overwhelming.
It came after a fraught exchange, in which Mr Corbyn reminded Mrs May the next meeting of the European Council was not until March two months after the rescheduled meaningful vote is supposed to take place.
He said: She will be bringing back the same deal she pulled last week – it’s an intolerable situation and she is simply playing for time.
Mrs May said her achievements with EU negotiators would be set out in the new year and again insisted Mr Corbyn had no alternative Brexit deal.