It depends on whether what they said was true or not.
The programme makers (as I said Panorama is rubbish nowadays) must be of that political persuasion otherwise they wouldn't have made the programme.
What you are proposing would mean no programmes exposing the weaknesses of any political party.
If you want to complain about a local issue, would you contact a councillor who you knew disagreed with you or one that did agree with you?
Neutrality out of the window then.