Last Night's TV: Hattie/BBC4<br />Mary Portas: Secret Shopper/Channel 4

Hattie Jacques is cooking Christmas dinner for family and friends, and it's not going entirely well. One of the turkeys has been burned and, as Hattie is giving the gravy a stir, the ash from her jutting cigarette drops into the saucepan. "Don't tell anyone about the secret ingredient," she hisses at the friend standing next to her, and quickly stirs it in. The subject of Stephen Russell's biopic Hattie – the latest in a line of BBC4 dramas about the private lives of television's early public figures – was the rather more interesting secret ingredient that Hattie was about to add to her marriage a live-in lover called John Schofield, who displaced John Le Mesurier from the marital bed and sent him into glum exile in the attic.

Russell began with a prelude; a Rome hotel room and the sound of a blazing row off screen, ironically accompanied by Tony Bennett crooning "The Good Life". This was, we were led to understand, the end of the affair. Its beginning (if this wasn't one of the moments of embroidery the script confessed it had allowed itself) occurred when Jacques was being driven back from a charity event and found herself drawn to the East End chancer behind the wheel. In this version, he rebukes her for her reflexive self-deprecation – a standard part of her public patter – and before long Hattie has melted. When Schofield turns up on the set of Carry On Cabby, it isn't long before the star's caravan is rocking gently on its chocks.

John Le Mesurier – nicely played by Robert Bathurst as polite hesitation in a Tattersall shirt and cravat, with a glass of whisky firmly attached – can't be said to have put up much of a fight. Schofield pushes the issue by leaving his wife and moving into Jacques's home, but when Le Mesurier enters a room to find the new lodger vigorously exploring Hattie's considerable bulk his only remark is "I'm terribly sorry!" Before long he has been dispatched to a single bed upstairs, and Schofield is esconced as Hattie's secret lover.

Ruth Jones played Jacques, a piece of casting that on paper may have seemed to make sense physically, but didn't entirely in practice. The problem was that she was just a little too sexy in the role, not really a match for the formidable homeliness of the original. And because of that you wondered whether an alternative explanation for this unexpected romantic development had been left in the shadows. This, it struck you, may have been one of those evenly reciprocated affairs in which desire wasn't matched at all: Jacques fell for a handsome young man who treated her as if she was Barbara Windsor, rather than the stock fat lady; Schofield fell for someone who had money and public status. And if that's too cynical an account of what was actually a genuine love affair all I can say is that the drama didn't really make you feel the romance.

You also couldn't entirely suppress the feeling that a biopic called "John" might have been more interesting, since Le Mesurier's part in this was fascinating, a collision of upper-class British reserve with bohemian sexual melodrama: "I know you're looking for some kind of fight," he tells Schofield at one point, "but I really think it would be incredibly vulgar, don't you?" Having ruled out fisticuffs, he then struck back with decorous restraint, concealing the fact that This Is Your Life was planning a programme on Jacques, a broadcast that painfully accentuated the gap between her public image and the private truth. I don't know whether he did it in the real programme, but in this drama's version he toyed with cliffhanger pauses and double-meanings that only those in the know would understand. Having thanked Jacques for keeping a happy family home, he then added: "For someone who's so very busy all the time and so much in the public eye all the time to do these things is very difficult... and a jolly neat trick." And then he did the unimaginably gentlemanly thing and took the blame for their divorce, to spare Hattie from a media monstering. John Schofield, as we'd known from the very beginning, didn't know how to bow out with grace.

In Mary Portas: Secret Shopper, Mary went undercover to reveal the fact that customer service is less than optimal in Primark and H&M. I'm not sure that "reveal" is really the word for a statement this obvious, but Portas appeared scandalised to find untidy racks and lethargic shop assistants in high street "fast fashion" stores. The fact that you can buy a party dress for the price of a Pot Noodle in these places may not be unconnected with this missing element in the retail experience, and the fact that she chose to film during a sale (in at least one outlet) may have had something to do with the queues and the chaos. Never mind that, though, as Mary was on a crusade, her sense of style extending even to elements of the business that most customers couldn't give a fig about. "It actually looks like a young offenders block – it is unbelievably bad," she moaned, arriving at the unprepossessing head office of Pilot, a small "fast fashion" chain. Well good. Perhaps what it saves on a swanky address and impressive atrium can be passed on to the customer. I bow the knee to the Queen of Shops (copyright BBC) and her expensive makeover for Pilot looked great fun. But it isn't only high-street brands that can run into trouble when they over-extend a franchise.

t.sutcliffe@independent.co.uk