His colleague John Thomson added: "These shows are produced by agencies who have their acts, and only their acts on those shows and it's not opened to everybody.
"It's a closed shop, which isn't right. That's why you see the same faces appearing on panel games."
In response, Flanagan told Digital Spy: "I think things have their moment - they come in waves. The sketch comedy wave was big and made a lot of people's careers, and made a lot of people very, very wealthy, and I think they should be pleased about that.
"I get a little bit worried when comics start saying that one thing is spoiling it for everyone else. If you think panel shows are genuinely spoiling comedy or making it hard - produce a really good sketch show, and you'll be surprised at how many TV companies jump on it."