Watch closely for the reaction of the PM and the Tory benches as Osborne asks Labour about their spending plans. Cameron’s face turns to shock as he and a number of other Tories point towards Labour MP Toby Perkins, sitting on the third row. From the video it is not clear why. Tory MPs are adamant this afternoon that it was because Perkins “flipped Osborne the finger”.

As Bercow intervenes you can hear a Tory MP shout “it’s Perkins!”. Guido is told that a Tory MP then passed a note to the Speaker making the allegation against Perkins, Bercow then ripped the note up and put it in his pocket. Perkins’ office are currently refusing to comment. All very parliamentary…