I can't speak for the UK market, but in the US, public radio is biased left. I'm biased right, so it annoys me, but I love the stuff that isn't political, like Click'n'Clack (did that come back or is it being rebroadcast?).
Commercial Radio has a non-government business benefactor, and so they cover what is of interest to them. Public Radio has government as it's benefactor, and so they cover their interests. Now it's not necessarily blatant, but whoever pays your bills, you have a self interest in seeing them in a positive light. If you are unable to do so, I'm sure you would move on to someone who you can see in a positive light. Bit of selection bias going on there, which is another slant maker.
I am fine with NPR, for example, having a bias to the left, but I wish they would stop pretending they didn't. Recognizing self bias is incredibly difficult, so it's not surprising when people don't see their own. This difficulty is as old as the bible (cf Matthew 7:3), and probably as old as thinking (I haven't read Plato or Aristotle but I would be surprised if they didn't talk about it.)
I have the same problem with Fox news, and really all the major news networks pretending to be unbiased, stating opinions as fact. I cut the cord a long time ago.
The more certain you are that you understand something, the less likely you are to examine it in depth. Do yourself a favor today, pick one of your beliefs, and take some time to examine why you believe it. Seek out some opposing positions, see if there is something to learn from them.
Do your best to find something other than "common sense" as the basis for believing what you believe.