If you feel an itch at the back of your brain in the next few days it's probably that karaoke classic Please release me wriggling to escape in a hum.

Almost 40 years since Engelbert Humperdinck topped the UK charts with this belter, and after a quarter of a century headlining in Las Vegas, with an estimated £100 million-plus fortune, and despite being a tad deaf, short-sighted and nudging 70, Humpers and his tune are back ... advertising John Smith's bitter. Undoubtedly the world's smoothest, leatheriest lounge lizard, Humperdinck joins Peter Kaye as the star of the latest belly wobbler from TBWA\London for the "no nonsense" bevy.

Now, this ad has an awful lot to live up to. The previous Kaye ads for the brand were just wonderful: superbly casted, beautifully written, truly funny, proof that a brand with a great advertising heritage can just keep getting better.

This showstopper ad, the first of the next batch in the John Smith's oeuvre, isn't the strongest, but it's still a major cut above the competition.

Set in a Las Vegas showroom, it's all neon glows and sequin glitz, tackier than a roll of Sellotape, everyone in their chain-store Sunday best.

Into this misty-eyed aspirational world rolls Kaye's right-between-the-eyes straight-talker, oblivious to the fact that's he's found himself in a temple of modern showbiz. And as Humperdinck takes a dramatic pause for his big end, Kaye interrupts and finishes the song.

What's lovely about the ad is the sense Kaye's own comic genius is being given a free reign. All too often agencies hire comedians, strip them from their natural material and straight-jacket them into an inappropriate script and it all becomes desperately unfunny; and, as that other so-called funny man Paul Kaye so crassly pointed out when he took the Woolworth's shilling to appear in their ads, the opportunistic celebrity can end up looking like a "c**t".

No such worries here. Peter Kaye's no-nonsense banter ("what time's bingo, mum?") at the end of the ad is a nice counter to the Las Vegas pseudo glamour. And Humperdinck (real name Arnold Dorsey, born and bred in Leicester, one of nine children who did pretty well for himself, a sort of Tom Jones without the groin) turns in a fair performance as himself.

Mind you, it's no wonder Kaye's comic talents might feel at home in this ad. It was shot at Lakeside, a tacky country club-meets-working men's club down in Frimley Green, Surrey. Lakeside is owned by Bob Potter, which might put you in mind of Brian Potter, Kaye's wonderfully resilient wheel-chair toting northern nightclub manager in Phoenix Nights. The Phoenix Nights club burnt down, as did Lakeside. Both were rebuilt by their respective Potters. It's a neat inside twist that Kaye should end up filming the John Smith's ad in the club that his Phoenix Nights show so closely resembles.

All in all it's another John Smith's triumph. Scrape back the great ads though, and the John Smith's brand is not exactly motoring. The bitter sells 1.3 million barrels a year, 400,000 more than its nearest competitor, Tetleys, and accounts for just over 14 per cent of the total ales market.

But that's pretty static year on year and the ales sector as a whole is in terminal decline.

It's interesting that of all the Scottish & Newcastle brands, the most high-profile advertising should come from the one with the least long-term prospects (Kronenbourg, which observers say has enormous potential and is perhaps under-performing, has forgettable advertising and a low marketing profile). Insiders say that where the John Smith's advertising has been really successful is in drawing new drinkers into this declining ale market. 'Ave it.

Dead cert for a Pencil? Maybe not as dead certy as the last batch, but

don't bet against it.

File under ... C for comic genius.

What would the chairman's wife say? "Ooo, Engelbert's still got it after

all these years."