Ed Miliband has branded David Cameron a "dunce" over his handling of the Royal Mail privatisation, prompting the Prime Minister to attack his Labour opponent as a "muppet" over his role in selling off the UK's gold stockpile.
The pair clashes in a heated Prime Minister's Questions, in which the Labour leader claimed the Government had "lost £1.4bn for the taxpayer" by undervaluing shares in Royal Mail.
As well as his attack over the sale of British gold - which took place when Gordon Brown was Chancellor - Mr Cameron claimed Labour had themselves wanted to privatise the Royal Mail.
"The truth is this. You sat in a Cabinet that wanted to privatise the Royal Mail, they couldn't do it... because the trade unions won't let them," Mr Cameron said.
Conservative MP Zac Goldsmith has highlighted that party leaders "fought to prove they were the greenest" during the 2010 General Election campaign.
Calling them "muppets," he wrote on Twitter:
In 2010, leaders fought to prove they were the greenest. 3 yrs on, they're desperately blaming their own policies on the other. Muppets.
His comments came after David Cameron promised to roll back "green regulation" imposed by the Labour Government
Commons Speaker John Bercow has ticked off David Cameron for using the word "conman" to describe Ed Miliband during Prime Minister's Questions.
This is not going well for Mr Cameron.
The Foreign Secretary William Hague has been criticised after he appeared to mouth "you stupid woman" at a Labour MP during Prime Minister's Questions.
Shadow Treasury Minister Cathy Jamieson asked the Prime Minister whether Tullow Oil chief executive Aidan Heavey's donations to the Conservative Party had influenced Mr Hague's intervention in a tax dispute involving the company.
Mr Hague, who was sat next to David Cameron, appeared to mouth "you stupid woman" twice as the Prime Minister answered Ms Jamieson's question:
Although Ms Jamieson did not comment directly on her Twitter account about the exchange, she retweeted comments that urge Mr Hague to apologise and call the incident "utterly despicable".
Five things we can learn from today's Prime Minister's Questions:
1 - MPs can be very loud - this was perhaps the noisiest session I have ever heard.
2 - Ed Miliband is trying very hard to get on the front foot over party funding after a terrible week
3 - David Cameron is still attempting to insert an answer on unions bankrolling Labour - no matter what the question
4 - Labour are now targeting the hedge funds they claim are funding the Tories
5 - People in the country might think there are more important issues to discuss during PMQs
The Prime Minister, referring to recent comments made by the Shadow Chancellor Ed Balls, said: "No wonder it's not just people at Wimbledon saying 'more balls please'."
Accused of missing the coalition's target of balancing the books by 2015, the Prime Minister countered: "We have cut the deficit by a third, we will have cut it more by the next election."
He added: "Why, if borrowing is the problem, is the Labour policy to put it up?"
The Prime Minister has accused Ed Miliband of being more suited to Sesame Street than Downing Street. He compared him to Bert from The Muppets.