[abb]

As it happens, at the moment both major parties (for different reasons) are threatening radical changes to the BBC

If they can enact the changes, then by definition they control it. I rest my case.

[Winniesboy]

‘Control’ implies day-to-day supervision or management, which doesn’t exist. They can, as you say, enact changes: but only through the cumbersome mechanism of periodic primary legislation. In theory, of course, such legislation could indeed introduce a mechanism for day-to-day state control: but as yet it hasn’t, it doesn’t now, and there’s little likelihood of it doing so in future.