IMAGINE if this worked the other way round. The BBC’s political editor Laura Kuenssberg is trying to ask a question of David Cameron and her words are drowned out by a bunch of posh-boy yobbos shouting. What would we think of that?

Not a lot, I would say. Yet this is what happened yesterday – with the only difference being that Labour supporters at a pro-Europe speech by Jeremy Corbyn started booing and hissing when Kuenssberg was invited to ask a question. The Labour leader reportedly had to shush the crowd before the Beeb’s political editor could speak.

Why did this happen? Many Corbyn supporters are obsessed with bias and believe that Kuenssberg has it in for their man. A little like followers of a religion, they react with holy anger whenever they feel their sainted hero is being treated unfairly.

There are a number of possible explanations. The first is that the criticism is true (I don’t believe it myself, by the way); the second is the role of social media; the third is the strong support Corbyn enjoys from new supporters who came from outside of the old-style Labour party.

Add those three strands together and you get a big knot of a conspiracy theory.

So is Kuenssberg biased? Well, this is partly a matter of taste and interpretation. I’d say some of the criticism was a misunderstanding of how a political journalist works, perhaps how any reporter works. By its nature the job involves asking sometimes confrontational questions of political leaders. Kuenssberg took on the role when Corbyn was newish to his role, and so he was a big political story. And whenever she asked anything considered ‘unfriendly’ by the Corbynistas, they reacted angrily, and then took to social media to complain.

Social media platforms sometimes act as an echo chamber for the like-minded: people gather in a dispersed mob, moan and shout, and then assume they must be right in their beliefs because everyone around them is making the same point.

Then you add to that left-wing websites such as The Canary, where many of the complaints about the BBC originate. This site says of the latest row: “The mainstream media has closed ranks to protect the BBC’s political editor, Laura Kuenssberg, but the public aren’t falling for it.”

And by ‘the public’ they mean all those people who think the same as they do. Nothing wrong with that as such; nothing wrong with such websites adding to the political variety of life. Except that they are as biased as everyone else, and more openly so than the BBC ever is; biased in the way that, say, the Daily Mail or the Telegraph are, but from the other perspective.

Interestingly, the phrase ‘mainstream media’ is used pejoratively to embrace just about everyone else apart from websites such as The Canary. The Guardian and the Observer, newspapers of choice to many an old leftie, are often swept up in the general contempt felt by this alternative media. And in my world, if those two newspapers aren’t to be trusted, then who is?

In the end all this hating of Laura Kuenssberg and the BBC is an unhelpful distraction for Jeremy Corbyn and Labour. Instead of complaining all the time, Labour needs to make better efforts to use television and other media to put across its messages. It’s a game that has to be played in this country, and standing on the touchline saying “It’s not fair” won’t get you very far.

And imagine if the Kuenssberg-haters got their way: a BBC political editor would have been removed by pressure from a political party or its supporters. What a frightening precedent that would set.

Incidentally, another possible explanation for all this is that David Cameron mostly favours stage-managed occasions at which he is asked no difficult questions. And that’s why it was good to see him pushed on the defensive yesterday on Sky News during the first major TV event of the EU referendum campaign.

If the BBC is failing somewhere in its political coverage, the problem lies in not asking enough questions of the prime minister, I’d say.