As revealed by a senior controller.
Ben Stephenson, the controller of BBC drama commissioning, said that the corporation should encourage "peculiarity, idiosyncrasy, stubborn-mindedness, left-of-centre thinking."
Mr Stephenson then tried to excuse his bias by claiming that the phrase had no political meaning.
"Like 'left-field', it is a phrase that I use with frequency when talking to the creative community to encourage them to develop and approach their ideas from a completely new perspective," he said.
In which case Mr Stephenson is either a fool - and I don't think that someone that stupid should be a controller in the BBC - or is being deliberately disingenuous. Unless he is a complete idiot he will know damn well that "left of centre" is a political phrase meaning socialist. He'll also know that it does not mean the same as "left field" and is not interchangeable with that expression.
I don't think Mr Stephenson is a fool - I think he knows only too well what is meant by "left of centre" and slips it in to promote his own particular choice of politics - and I believe he is far from being the only one who is left of centre in the BBC who does this. I think he's got so used to doing it unchallenged that it didn't occur to him that some people might disagree with him.