The Labour leader faced a furious backlash from Tories and his own MPs after appearing to mouth the jibe during a stormy Commons session.
In a brutal pre-Christmas exchanges, Mrs May had accused Mr Corbyn of descending into ‘pantomine’ over Brexit, saying his own party was not behind him.
But as the PM said down to cheers, Mr Corbyn seemed to mutter: ‘Stupid woman.’
The remark was not picked up on microphones, but politicians from both sides of the House were in little doubt what he said.
Virtuoso percussionist Dame Evelyn Glennie, who is deaf and can lipread, agreed with the interpretation. Bizarrely, Hollywood actor Rob Lowe also waded in, saying he had seen the insult ‘with my own eyes’.
When the slur was raised with her in the chamber, Mrs May retorted that all MPs must refer to women in an ‘appropriate’ way.
And after PMQs ended the House descended into chaos as Tories demanded Speaker John Bercow haul Mr Corbyn back to apologise.
Mrs May had said Mr Corbyn’s position as descending into ‘pantomine’, and said his own party was not behind him
Labour leader Jeremy Corbyn appeared to mouth the jibe as the pair faced off over Brexit in a stormy Commons session
The remark was not picked up on microphones, but politicians from both sides of the House were in little doubt what he said
Tory MPs beseiged the Speaker after the incident offering to show him visual evidence of what Mr Corbyn muttered
A spokesman for the Labour leader insisted he had said ‘stupid people’.
Tory MP James Cleverly said: ‘Jeremy Corbyn clearly calling @theresamay a ‘stupid women’ at #PMQs today. This kind of misogynistic language must not be tolerated.’
Labour MP Stella Creasy said: ‘This is not ok. PMQs is a hotbed of emotions but I hope that Jeremy will accept this kind of behaviour isn’t his normal good nature or what we expect of progressive men.’
Even shadow trade secretary Barry Gardiner waded into by criticising Mr Corbyn.
‘It certainly seemed like he might have done it… I’m sure he will regret it,’ he told BBC’s Politics Live.
Health Secretary Matt Hancock wrote on Twitter: ‘The mask slips. Jeremy Corbyn’s abuse of the Prime Minister shows what a reactionary misogynist he is’
He added: ‘Unreal how Corbyn supporters are actually *defending* him calling the PM a ‘stupid woman’. Sickening. This misogyny now runs deep in Corbyn’s Labour – and runs right to the top.’
The apparent remark caused uproar in the chamber as MPs became aware of what had happened.
Tory MP Paul Scully asked Mrs May if she had noticed the comment.
Mrs May responded: ‘I think that everybody in this House particularly in the hundreth anniversary of women getting the vote should be encouraging women to come into this chamber… and should therefore use appropriate language.’
A spokesman for Mr Corbyn said afterwards: “He did not call her a stupid woman and so I don’t think there’s any basis for an apology.
“As I understand it, he said ‘stupid people’.” The spokesman said Mr Corbyn was referring generally to MPs who were not taking the issues being debated seriously.’
Leader of the House Andrea Leadsom raised a point of order to refer to an incident earlier this year where Mr Bercow was accused of calling her a ‘stupid woman’
Bizarrely, Hollywood actor Rob Lowe – who starred in classic US political drama the West Wing – also waded in, saying he had seen the insult ‘with my own eyes’
A clearly livid Mr Bercow insisted he had already ‘treated’ on the issue
Conservatives also turned their fury on Speaker John Bercow.
Leader of the House Andrea Leadsom raised a point of order to refer to an incident earlier this year where Mr Bercow was accused of calling her a ‘stupid woman’.
‘If individuals who are found to have made unwelcome remarks should apologise, why it is that when an opposition member found that you had called me a ‘stupid woman’, you did not apologise in this chamber?’
After repeated jeers and banging from Tory MPs, Mr Bercow said: ‘No no I’ll deal with the point.
‘I dealt with that point months ago in remarks that I made to the House of Commons to which Ms Leadsom in our various meetings since has made no reference and which requires from the chair today no elaboration whatsoever.’
The Speaker added that ‘the matter has been treated of and I am leaving it there’.
She said when evidence was presented that ‘you had called me a stupid woman you did not apologise in this chamber’.
But former minister Anna Soubry then rose to claim that if the Tory MP had said the same thing to a Labour MP ‘you sir would take action immediately’.
‘With great respect to the chair I have to say this, if it was one of my male colleagues on this side of the House that had used that expression against a woman on the frontbench on the Opposition you sir would take action immediately.
‘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.’
Mr Bercow, who was being shouted at and heckled by Tory MPs, responded saying: ‘I cannot be expected to deprecate the behaviour of an individual which I did not witness.’