Just like pop, Room 101 has finally managed to eat itself. For too long, the show has teetered on the brink of mediocrity, threatening to sink forever into that particular abyss. With each passing edition, the format looks ever more tired and wrung out. Sporadic scintillating slices of comedy still appear (last week’s Boris Johnston performance, for example) but these occasional gems are increasingly fewer and farther between.

Even the redoubtable Paul Merton looks a pale imitation of his Have I Got News For You self; embarrassed to be there almost. Despite his assured stewarding of the show, the palpable truth laid bare is that this noteworthy dog has well and truly had its day. Which is a pity as Room 101 has provided the viewer with many a happy comedic memory. But these memories are being slowly, but surely, sullied by the overwhelming onslaught of tedious unevenness being offered up in recent times.

Tonight’s edition encompassed some of the major problems currently inherent in Room 101 – the wrong type of guest, the dull choices, the forced banter, the weak scripting. The trailer that proclaimed Linda Smith to be “the wittiest person on Radio 4″ was, on this evidence, sadly misjudged. With a voice that could turn milk, Smith may be a fine stand-up and an assured wit, but sadly here she failed miserably. Her choices were thoroughly uninspired and said much more about her than anything else. The chip on her shoulder was evident from the off and the “I know best” arrogance permeated the programme constantly, to the extent that you felt almost as if you were wading through her bile by the close of the show.

Starting off with pop at adults who read Harry Potter, her dogmatic but intellectually anorexic arguments failed to back up her choices spectacularly. Leaving aside the ridiculous (and risibly pathetic) notion that adults shouldn’t read children’s books, Smith revealed the paucity of her intellect by railing that those adults should instead be reading Madame Bovary. Just like the cerebral deadheads who argue along similar lines in The Big Read, the notion of “proper” books is bordering on the fascist. The conceit that Candide is superior to The Voyage of the Dawn Treader solely because it is a “proper book” is as tragic as it is fallacious. In the best of all possible worlds, one cannot even countenance this erroneous hypothesis. I’ve ploughed through Bovary and, God knows, it’s dull beyond belief. It was, for me, one of those tomes that after reading you couldn’t help but think that that was a slice of your life you’d never get back.

Smith’s argument that by reading Harry Potter and The Lord of the Rings these adults were doing society harm was an inane observation that deserves to be treated with patronising contempt. On this showing in front of a supine audience and an encouraging host, her lack of improvisational skills were shocking.

Raging against the machinery of bow ties, comic opera, “back to school” signs and Tim Henman fans, Smith continued to pettily snipe at her intended targets – the middle and upper classes. An unlikely class warrior, the usual secondary scapegoats were trotted out – Bernard Manning (a comic who could, comically, literally and figuratively, eat her alive), golf, The Daily Mail and toffs in general – and a scattergun was taken to them with no effect whatsoever. This was miss and miss stuff, symptomatic of the malaise that pervades Room 101. Smith, unlike Boris Johnson, is clearly unable to laugh at herself: a deep, deep flaw for a guest on this programme. Whereas the most entertaining leader a political party could ever have is patently aware of his foibles and plays to them with a childlike sense of mischief, Smith belongs to that school of though that proclaims I am funny, so you’ll laugh with me. As they’re fond of saying at pantomimes the land over, oh no we won’t.

Room 101 currently has an air of all too chummy bonhomie wafting about. The guest list needs to be looked at and expanded dramatically if the show is survive in its present format. When you’re faced with a nonentity like Ronan Keating parading his bête noires to the nation then you know your number is up. As much as I admire Merton, I have to profess to a preference for the previous host, Nick Hancock. As talented and engaging as Merton is, he’s not a natural host and, on occasion can seem somewhat stilted and uncomfortable in that chair. Compared to, say, Stephen Fry on QI or Mark Lamarr on Never Mind the Buzzcocks Merton is plainly not in their league. Whereas Fry and Lamarr can play to the panelists, the audience and the camera simultaneously with a certain amount of élan, Merton seems to be incapable of drawing all the components in and creating a sense of wholeness.

For me, Room 101‘s time has passed. The joke wore paper thin a long, long time ago. I really can see no future for it and it’s clogging up a half-hour of the schedule which could be put to far better use. Like placing Linda Smith in a roomful of Tim Henman fans. Now, that would be worth watching.