Theresa May said Jeremy Corbyn should start “tackling injustice” and antisemitism allegations inside his own party before he criticises the government.
In a fiery Prime Minister's Questions, Mrs May said that if Mr Corbyn was “really interested in tackling injustice, then the biggest injustice he should tackle is in his own party".
She referred to non-disclosure agreements handed out to Labour staff, despite the party calling for a ban on them.
“Labour policy is to ban non-disclosure agreements, but his staff has to sign them. He was an anti-racist, now he ignores antisemitism. He has been a Eurosceptic all his life, now he backs remain,” she said.
“He is truly living up to the words of Marx. Those are my principles and if you don't like them, I've got others.”
The comments elicited a strong response from the Commons, and Ms May continued her verbal assault over the shouting.
“I know the Rt Hon Gentleman is keen to get to the dispatch box when the name Marx is mentioned, but I was merely going to point out that those were the words not of Karl, but of Groucho,” she added.
A visibly angry Mr Corbyn said Mrs May refused "to acknowledge Islamophobia in her own party” and accused her of consorting "with racists and antisemites in the European Parliament”.
In a more united moment of PMQs, the party leaders paid tribute to Sir Kim Darroch, who retired as the UK ambassador to the US earlier today after his private emails about Donald Trump were leaked to a newspaper.
Ms May said she wants all public servants to have the confidence to give “full and frank advice”.