Not sure about GB news, but Question Time was broadcast from my workplace last year and lots of us were excited and filled out the application form to appear in the audience. It asks your political leaning, thoughts on Brexit, who you will vote for in the next GE, your ethnicity etc.
Three left and one right wing colleagues got a golden ticket. One even got his noggin on screen by having a question and Fiona Bruce calling out his name. We were all dead excited...like oooh don't they make (workplace) look nice...not like that in real life!
I like to think there is no bias in the selection. Surely it helps the debate to challenge views? If not, what's the point?