The stereotype of a feckless, underclass – irredeemably indolent, congenitally doomed to a life of welfare dependency – has been with us for as long as there have been politicians and tabloid newspapers to exploit it. As James Morrison observes, there is very little evidence to support the theory that chronic unemployment is passed down the generations like a hereditary illness: research indicates that such families account for less than half a per cent of all workless households. And yet this tiny minority looms disproportionately large in popular culture, invariably as the subject of complacent sneering or smug voyeurism – from Little Britain’s Vicky Pollard to the “poverty porn” of Benefits Street.

James Morrison argues that a series of legislative interventions dating as far back as the 14th century have had the effect of gradually eroding public sympathy for the poor. A 1349 Ordinance aimed at weeding out fraudulent “sturdy beggars” contained an “enforced labour” clause requiring any fit unemployed person to “serve him who shall require him”. From this point on, Morrison writes, “statutory seeds of suspicion were sown about … the honesty of those pleading poverty”. The 1834 Poor Law Amendment Act sought to discourage claimants by making access to handouts contingent on entering a workhouse. The stigma and mistrust engendered by such measures was compounded by successive vagrancy laws which “discursively pathologised paupers’ behaviour as a threat to both social and moral order, ultimately reframing them as criminals”.

Victorian-era anxieties about the idle poor may have owed as much to the utilitarian ideas of Jeremy Bentham and Thomas Malthus as to the Protestant work ethic, but the influence of religion should not be underestimated. In our own time, several of the most enthusiastic advocates of the “tough love” approach to welfare – Gordon Brown, Tony Blair and Iain Duncan Smith – have been men of faith. Morrison notes that although Blair had talked of wanting to reintegrate the socially excluded into mainstream society, “New Labour’s rhetoric had the symbolic effect of further separating his ‘workless class’ from the respectable poor’’. The notoriously intrusive work capability assessments for disabled claimants came into operation under Labour in 2008; Duncan Smith took up the baton when the Tories came to power in 2010, introducing draconian “claimant contracts” whereby jobseekers who turn down work could be stripped of their benefits under a “three strikes and you’re out” rule imported from the criminal justice system.

After revisiting a number of characteristically sensationalist Daily Mail exposés of benefits cheats, Morrison laments the relatively equivocal nature of the “counter-discourses” proffered by the liberal press. He contends that, by focusing their attentions on manifestly worthy sub-groups such as the elderly, well-meaning journalists have unwittingly internalised a framework that privileges “deserving” claimants over “undeserving” ones. This is a fair point, but elsewhere in Scroungers the author’s idealism grates. Morrison has a regrettable tendency to dismiss progressive reform initiatives as inherently paternalistic and patronising, and he is at times over-zealous in his policing of language. Upbraiding Marx and Engels for their use of the term lumpenproletariat – on the grounds that it is dehumanising – and calling out Labour radicals Beatrice and Sidney Webb for having once remarked that extreme poverty had rendered some people “unemployable” is little more than discursive nitpicking.

Facebook Twitter Pinterest Margaret Thatcher: the biggest rise in the number of economically inactive people happened under her governments. Photograph: Jane Bown/The Observer

This quibble aside, Scroungers makes many salient and persuasive arguments, most notably regarding the incompatibility between the abstract fetishisation of work and the grim reality of neoliberal Britain. Margaret Thatcher famously sought to position the Conservatives as the party of “the workers and not the shirkers”, but Morrison notes that “the biggest rise in the number of economically inactive people” happened under her tenure, which normalised the idea that a permanent mass of unemployed was a price worth paying for a dynamic economy. He rightly points out that the rhetorical dichotomy that pits “hardworking people” against the unemployed overlooks “the inconvenient truth” that in a neoliberal labour market increasingly predicated on “zero hours” contracts and precarious employment, “it is possible (even usual) for one and the same person to be both hardworking and unemployed”. As we stand on the threshold of an era of digital automation which threatens to render ever greater swathes of the population surplus to economic requirements, the longstanding socio-cultural compact that equates industriousness with moral worthiness may become even more untenable.

If the media today seem marginally less obsessed with “scroungers” than they were in the years of Blair and Brown, this may be because, since 2010, Tory austerity has been busily doing the work of hammering the poor and the needy. The publication in 2012 of Martin Amis’s novel Lionel Asbo, about an archetypal underclass oik, was noteworthy for its conspicuous untimeliness: this kind of thing had had its moment, and Amis had missed it by a cool decade. Yet scapegoating the undeserving poor remains a potent political weapon, and any demagogue worth their salt will avail themselves of it. In the runup to the 2016 Brexit referendum, much of the anti-migrant rhetoric emanating from the rightwing tabloids emphasised the strain that uncontrolled immigration was putting on the public purse. When the leave campaign mendaciously hyped the prospect of Turkey joining the EU and millions of Turks thereby gaining legal access to our shores and social security system, it raised the spectre of what Morrison calls a “toxic scrounger/invader hybrid” – two bogeymen for the price of one. It worked.

• Scroungers: Moral Panics and Media Myths by James Morrison is published by Zed Books (£18.99). To order a copy, go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £15, online orders only. Phone orders min. p&p of £1.99.