MPs who "shout their heads off" in the Commons are "downmarket", stupid and do nothing to reconnect a disillusioned electorate with politics, Speaker John Bercow has said.

Mr Bercow admonished MPs as they barracked each other during shadow chancellor John McDonnell's response to George Osborne's Autumn Statement.

Mr McDonnell was accusing the Chancellor of missing his own debt and deficit targets before he was drowned out by shouting Conservative MPs, who were then met with more howls from Labour opponents.

Mr Bercow described MPs' behaviour as "pitiful".

Intervening, the Speaker said: "Both sides are still shouting their heads off, it's very downmarket, it's very low grade, it's very widely deprecated by the public.

"How it is that people think that it's legitimate to behave in that way and try to reconnect with the electorate disillusioned with politics is just bizarre?

"Some people are so unintelligent they still can't grasp the point, I pity them.