Amid today’s Commons warfare over the Queen’s Speech, David Cameron had a response to Harriet Harman that few in Labour's ranks will have anticipated.

Labour's acting leader slammed the Tory policies on families, welfare and extending right-to-buy.

She also had a bit of advice for Dave:

"Beware the blonde on the zipwire."

And she joked that she may not be so different to the PM after all:

“Although he and I have many differences... in many ways we are quite alike. We are both, by our own admission, interim leaders.”

But in his comeback, Cameron moved quickly to reject any suggestion that the pair were cut from a similar cloth.

"I was racking my brains to think what we had in common, because of course she's far posher than I am."

While Labour MPs snorted with derision and Harriet did her best to look utterly incredulous, did the PM have a point?

For the record, Cameron went to Eton and his maternal great-grandfather was Sir William Mount, 1st Baronet, CBE, Conservative MP for Newbury.

Harman went to St Pauls, her aunt was Elizabeth Pakenham, Countess of Longford and she is a great-great niece of Joseph Chamberlain.

Not that it matters at all...