The BBC, to me, over the last 2-3 years has demonstrated massive pro-Conservative party bias. The mechanism for that is not apparent, but look at Kuenssberg and you see someone who has regularly been followed by accusations of strong bias with ultimately, it seems, nothing being done about it. To my view she (or the team she's in?) directly interfered in the last election; she didn't seem to be hindered in any way. Someone caught divisively lying on several occasions (each damaging Corbyn/Labour) yet remaining in post says to me their is political control over the BBC. She did grill Johnson after the election when it no longer mattered though.
Ironically Radio 4 (taken as a whole) seems to provide a reasonably level playing field; but their listeners are a small fraction of BBC1's viewers.
I think the parties involved are smart enough not to leave evidence lying around in public. The "postal vote" debacle was either a direct attack on democracy, out in the open, or a complete failure of the entire editorial team that should have seen them immediately sacked.
Interestingly the Cabinet Secretary, head of the civil Service - which headlines itself as having open public recruitment - was chosen by Johnson on entry to Downing Street.
My personal opinion is this is a drip-drip-drip erosion of balance to allow the current government fascististic levels of control.
Most recently reports are that some satirical comedy shows are being stopped as the government see them as too critical of Tories and not critical enough of others (they must have forgotten who is in power). How is it possible the BBC aren't being interfered with in removing some of their most popular domestic broadcasting when the only extent reasoning is 'to reduce on-air criticism of the current government'.
I'm sure you'll wave your hand and say this is all anecdote. In general Trump's playbook has been copied by Johnson, control of media/reporting is a part of that.
The BBC is fully independent and there are multiple levels of oversight to ensure that. I'm sure you can furiously Google a more apt response than that. Evidence please
Who was in power all that time?