Every so often he forgets he's meant to be nicey nicey Tory and reveals his true self, which involves treating his opponent like a schoolboy bully and is on about the same intellectual level.
He does it when he's stressed/under pressure. He normally turns red at the same time. Maria Eagle's heckle is embarrassing, because when your own mother isn't supporting you, who is?
John Crace nailed this in the Gruniad:
http://www.theguardian.com/politics/2016/feb/24/cameron-strays-from-the-script-with-corbyn-do-up-your-tie-jibe
Every so often he forgets he's meant to be nicey nicey Tory and reveals his true self, which involves treating his opponent like a schoolboy bully and is on about the same intellectual level.
He does it when he's stressed/under pressure. He normally turns red at the same time. Maria Eagle's heckle is embarrassing, because when your own mother isn't supporting you, who is?