PMQs: Cameron on Bletchley codebreaker Alan Turing

David Cameron said the work by codebreaker Alan Turing and others at Bletchley Park in Buckinghamshire was "absolutely vital" in winning World War 2.

He was responding to Conservative MP Iain Stewart who thanked those for granting the posthumous royal pardon to Mr Turing, which he said had "finally seen justice for this national hero".

This overturned his 1952 conviction for homosexuality, after which he was chemically castrated.