Gillian Reynolds

This show finds comedian Ava Vidal on the trail of the lonesome joke, arguing that there are no laughs left in Westminster now devolution has left a hole at the centre of the mirth. Stay tuned for gales of merriment from Edinburgh, Cardiff and Belfast.

Radio 2 is celebrating British comedy so here's Leslie Phillips, the king of onscreen leer and chuckle, with a salute to the Carry On films which, for half a century, packed cinemas and, to this day, score highly with TV audiences. Was it because they related so closely to the events of their times (National Service, the NHS, holidays at home, holidays in Spain) or that their characters were archetypes as old as Chaucer's? Fellow Carry On actors reminisce with Phillips, clips from the archive recall those who have gone to the great sequel in the sky.

Hard to imagine why Kim Fuller's nimble comedy is going out here when, nightly at 6.30pm, there's mainly preaching and screeching. Here's the start of a new series of medieval goings-on, with wonderful James Fleet as Sir John, bewildered by his children, at the mercy of twists of fate which sound very familiar to modern ears. It's the age of dungeons but everything (apart from Merlin's talking sausages) is pretty much like today, from WAGs being forbidden to go with their knights on Crusades, to Sir John Chilcot's enquiry into Dragons of Mass Destruction.

Lord Emsworth (Martin Jarvis) is getting Empress of Blandings, his prize pig, ready for the Shropshire Agricultural Show. He's worried about possible nobbling by rival breeder Sir Gregory Parsloe (Michael Jayston). Meanwhile scandal looms if Emsworth's brother Galahad (Charles Dance) publishes his memoirs so Parsloe hires private detective Percy Pilbeam (Matt Lucas) to nick the manuscript. And love, as ever in a PG Wodehouse comedy, is making life very complicated for the younger set. Dramatised in two star-studded episodes by Archie Scottney, made by glamorous independents Jarvis and Ayres Productions.

You'll recognise the name of Bill Dare as creator/producer of such programmes as Dead Ringers, The Now Show and I've Never Seen Star Wars. Here's a new series of a more recent invention, intertwining fantasy with the familiar. Lionel Blair, for instance, is mistaken for Tony Blair and has to go to the Middle East to get the leaders "dancing to the same tune", Al Pacino stalks John Humphrys. William Hague talks to the Ambassador of Kyrkistan having been mistakenly briefed on Uzbekistan. Jon Culshaw and Lewis MacLeod are among the skilled vocal parodists.

First of a pair of charming plays (there's another tomorrow) by Michael Chaplin about William (Richard Briers) and Sandy (Stanley Baxter), two residents at the Old Beeches retirement home for theatricals who, when the call comes, can set their differences aside and solve the occasional mystery. Today's involves Charlie (Barry Cryer), an elderly comic. His joke book goes missing and, with it, quite a lot of money. But it's a delicate situation, one that will soon call for all the tact that our duo of tetchy amateur sleuths can muster.

ISIHAC raises just a single snigger

I'm Sorry I Haven't a Clue is a sad show now, the ghost of what it was. I never thought the day would come, and I really wish it hadn't, but I sat through last night's start to the new run with one smile and a single snigger.

I'm Sorry I Haven't a Clue returns with Jack Dee in the chair solemnly reading his script and distributing questions. The audience (in Cheltenham) roar their appreciation throughout. In fact, the Clue participants seem under the dangerous delusion that they're at some private party rather than doing a radio show.

New four-part comedy of the reflective kind, set in a small town bubbling with hope, fear and mistrust, a bit like an inland English Under Milk Wood, faintly reminiscent of Peter Tinniswood's lively studies in eccentricity. By Katherine Jakeways, it has the great benefit of Sheila Hancock as narrator, Mackenzie Crook as Rod, the supermarket manager, and the author herself as Esther, the very assertive instructor of both driving and judo. The overall plot is how they're all getting ready for a talent night, produced by Mary (fab Penelope Wilton).

Last week Radio 4's Afternoon Play was full of such temptation. In Gary Brown's comedy Prospero, Ariel, Reith and Gill (Wednesday), John Reith, the BBC's first director general (played by Tim McInnerny) faced up to his inner sexual demons, as did the sculptor Eric Gill (Anton Lesser), finishing off his famous Prospero and Ariel statue over the doorway to Broadcasting House. Because it was full of obvious signals (funny voices from Jon Glover, comic whizzing noises) we were clearly warned not to take it literally. Yet there seemed an earnest hankering, in the confessional bits, to show us the author's solemn side too. Mistake.