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.
The Business Secretary says he has no intention of apologising over Royal Mail shares which rose sharply in value on the day they were sold.
The government sold it's 60% stake for £1.98 billion but more or less ever since has been accused of short-changing the taxpayer.