Ian Blair and Tape Recording

Ian Blair, the Commissioner of the Metropolitan Police, has been in trouble for tape recording conversations with members of the government. To my mind this is only sensible and I can't understand why it isn't common practice. Admittedly there are security concerns - the recordings would need to be secure. If nothing else, they could provide a valuable historical document (re: the Kennedy tapes made at the time of the Cuban Missile Crisis). I can fully understand why an impartial record of a conversation with the Powers That Be could be seen to be desirable. I think I heard on the radio that the tape was made as there was no notetaker present - I must admit to faling to understand why notes (which could be made in error) are okay, but a recording is not.

I'm not a lawyer, but if memory serves, taping a phone call is fine with consent. Without consent is it the case that the tape cannot be made, or that the tape cannot be played to a third party? (Edit: I find that this is the case)

I must admit to being amused that the conversation being taped was upon the subject of the use of intercept evidence.