British Opposition Leader Jeremy Corbyn has sparked outrage after being accused of making a sexist remark about Prime Minister Theresa May on the floor of parliament.

Lip-readers were scrambled when the Labour Leader was shown on camera Thursday morning (Australian time) appearing to mouth the words “stupid woman” after a lively Question Time exchange with the Prime Minister.

Mr Corbyn had been peppering Ms May with hostile questions about her decision last week to postpone a parliamentary vote on her unpopular divorce deal with the European Union.

In reply, Ms May had suggested Mr Corbyn might not enjoy the support of his own MPs over the EU and, taking a well-worn line from Christmas pantomimes, had said: “I’ve got some advice for the Right Honourable Gentleman – look behind you!

“They are not impressed and neither is the country!”

Mr Corbyn then shook his head and appeared to mutter “stupid woman” under his breath.

You be the judge:

https://twitter.com/sw1a0aa/status/1075367092336115713

Alerted to the incident, Ms May later told MPs: “I think that everybody in this House – particularly in this 100th anniversary of women getting the vote – should be aiming to encourage women to come into this Chamber … And should therefore use appropriate language.”

Mr Corbyn later denied he had used sexist language.

“During Prime Minister’s Question Time today, I referred to those who I believe were seeking to turn a debate about the national crisis facing our country into a pantomime as ‘stupid people,'” he told the House of Commons.

“I did not use the words ‘stupid woman’ about the Prime Minister or anyone else, and am completely opposed to the use of sexist or misogynist language in absolutely any form at all.”

Mr Corbyn’s explanation was met with scepticism among UK politicians and sparked intense debate among the British public, and even prompted former West Wing star Rob Lowe to weigh into the debate.

FYI- I have to say, I saw Jeremy Corbin call the Prime Minister a “stupid woman” with my own eyes watching on @SkyNewsPolitics

— Rob Lowe (@RobLowe) December 19, 2018

The Speaker of the House of Commons, John Bercow, said he examined footage of the incident and couldn’t be certain what was said.

“I am not a lip reader, or indeed a lip speaker. Nobody can be 100 per cent certain – that includes professional lip readers – but I will naturally take, and would be expected to take, the word of any member. It is reasonable to expect the House to do the same.”

The Leader of the Commons, Conservative Andrea Leadsom, said that she “deeply” regretted that Mr Corbyn had not apologised to Ms May.

“I think that the country and this house would have drawn their own conclusions,” Ms Leadsom said.

It was not the first time that a row had blown up over the alleged use of the “stupid woman” phrase in parliament.

In June, Mr Bercow himself was alleged to have applied it to Ms Leadsom.

The Commons standards watchdog at the time decided he should not be investigated.

-with AAP