Behind the Scenes at the Museum, BBC4 <br> All at Sea, ITV1

Not long after Margaret Thatcher was ejected from Downing Street by renegades in her own party, a strain of heretical thought became fashionable in Tory circles. This new, dissenting view held that, far from advancing the cause of conservatism, Britain's first female Prime Minister was in fact antithetical to it. She claimed to espouse a return to Victorian values yet her embrace of Chicago School economics had shattered the local attachments and small institutions – Burke's "little platoons" – that both stimulated and rewarded the conservative disposition.

As John Gray, who has achieved subsequent fame as an iconoclast, put it in the most influential essay sponsoring this contrarian position, "market forces – especially when they are global – work to unsettle communities and delegitimise traditional institutions". A "cult of the free market," he wrote, showed "conservatism has colluded with the spirit of the age."

A Conservative once again occupies No 10 Downing Street. Yet for all that he reeks of the Establishment, David Cameron has in a fundamental sense repudiated Thatcherism. Our "broken society" was partly caused by the inequality of the Eighties, he admits; he gives speeches on the need to erect "general wellbeing" indices alongside those for "gross domestic product"; and his domestic policy is aimed at restoring fraternity through small, local institutions (including the family).

This reaction to Thatcherism stems from a world-view that lauds the quiet, the familiar, and the aged. It is, above all, nostalgic. Recent events have shown it to be in the ascendant, attaching credence to T H Huxley's marvellous observation that "it is the customary fate of new truths to begin as heresies and to end as superstitions". Social conservatism, alas, is in the air. A lot of people think we need to be go back to an age of solid objects, reliable hierarchies, and trusted brands. And they have BBC4 to give it to us in pictures.

This station, easily the best in Britain, has industrialised nostalgia. Not just any old, my-first-shag nostalgia; rather, an aching, tangible, indefatigable, and ultimately defeatist nostalgia for former glories, one at home more in the conservative than liberal temperament.

I hereby venture that, stiff competition notwithstanding, no BBC4 programme captures this generalised wistfulness with quite the efficacy of Behind the Scenes at the Museum. Its hagiography of the British Commercial Vehicle Museum in Leyland, Lancashire, is impossibly charming. Here, just metres away from the factory of what was once the largest motor manufacturer in the world, is a parable of both industrial decline and futile resistance to the march of history.

An army of silver-haired volunteers, many of them retired Leyland workers, defy leaking roofs and their own relative poverty to fix, polish, and re-arrange classic British vehicles that derive, in their own words, from an "age of elegance". "Take a journey through time," screamed a sparkling Green Goddess, and we did, having the sense of being in a giant Hornby set, full of toy models, an effect accentuated by the unmistakeably childish fondness for engineering shared by so many of the workers, each boasting an obsessive grasp of detail. Who could tell, listening to Bob extol the virtues of gear ratios and turning circles, that he was a septuagenarian, rather than just 16?

There was a stubborn anachronism about the volunteers – who, with names like "Pritchard" and former careers as tax inspectors, evoked a late-Victorian sensibility – that made each of them endearing. Our narrator united the underlying theme (nostalgia for a lost age) with both genuine drama (can the oldies sell enough tickets to survive?) and an exposition of what museums are for: first, making the dead live; second, creating social solidarity – fraternity – out of so doing.

Yet, watching the conclusion, it was impossible not to feel a sense of impending loss. Bob, alas, really is part of dying breed; we don't make these machines anymore; Shanghai, not Leyland, is where it's at; lost worlds cannot be remade. And, as if to confirm this, over on ITV1 there came proof.

All at Sea also deployed old machines – albeit giant fishing trawlers from the 1960s – and examined local history, in this case of the glorious south-western tip of England. But in using the modern method of installing D-list celebrities instead of normal people, it sacrificed authenticity for alleged flair, and lost informative power along the way. How very ITV.

Our household names endured the vagaries of life at sea while ruminating on Cornwall's history. As far as it goes, this isn't so bad, but it's hardly the pinnacle of creative television when a young developer asks his executive producer if he could get in touch with Bradley Walsh's agent and enquire how much he'll charge to seem interested in Penzance. It's just a bit mediocre, and boringly middle class, chaps: dare to give us real history, not fading TV stars.

Much like our Bob and his comrades, in fact. It's probably not healthy, this nostalgia lark, but then watching these shows in succession, the old does feel more real than the new. Last night, BBC4 was weirdly a depository of despair, and ITV1 a depository of D-listers. I despair of my preference for the former.

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a.rajan@independent.co.uk