It was the raw early days of the coalition, and one of David Cameron’s lieutenants was giving a frank answer to my blunt question: what would it take for the government to pull back on its planned cuts? You didn’t need a Mensa membership to see that this topic would define the next five years.

On that sunny autumn afternoon, the newspapers were full of students besieging Conservative central office, but Cameron’s aide coolly judged that they’d blown it by picking the wrong target. Had they swarmed on Lib Dem HQ “that would really have put Clegg under pressure”. So what would change Tory minds? “The crunch will come when the Mail puts on its front page pictures of some Iraq war veteran in a wheelchair who’s lost his disability benefits.”

That ugly logic has underpinned this government. Cameron and Nick Clegg have justified social security cuts by reciting a litany of false oppositions. Strivers v skivers. Workers v shirkers. The bedroom tax, the arbitrary removal of benefits from those infringing some bureaucratic small print, the judging of sick people as fit for work – £17bn of cutbacks have been sold by ministers, and bought by the public, as falling on the undeserving poor: the mickey-takers on a gigantic, taxpayer-funded bed-in.

What my contact foresaw back in 2010 was that if this political link were ever broken, and money seen to be taken from the plainly deserving, the central plank of austerity would snap in two. However, that Mail front page has never appeared, and yesterday Cameron was able to warn of Labour “chaos … higher taxes for every working family to pay for more welfare”. Even so, the Law of Welfare Cuts has just taken two shattering blows.

The first was delivered by the Conservatives themselves, in the form of a leaked paper discussing options to make more benefit cuts. Commissioned by the Tories, written up by senior civil servants and already under discussion by ministers, the proposals include taking allowances from about 40% of carers for the sick; the scrapping of government compensation for those who’ve suffered industrial injuries; and the taxing of disability benefits.

The Conservatives have tried to stamp all over this story, and with excellent reason. Where’s the justice in taking cash off someone who’s mangled an arm on a construction site, or who’s had to cut back on work to look after a sick child? These savings manifestly break the coalition law of welfare cuts: that they must be seen to be fair.

And they don’t even save that much money. As with so many “reforms” since 2010, these reductions would turn people’s lives upside down, plunge some into debt and tear families apart – and in some cases raise little more than loose change. It may be that we have passed the high tide of public support for cuts in social security – and it would be for exactly the reason predicted by that Conservative aide in 2010. The Tories have set a goal of cutting another £12bn a year from welfare by April 2017. This target is so stupidly implausible that it will force any future government led by Cameron into ever more manifestly unjust benefit cuts. That fictional divide between deserving and undeserving poor may be on the verge of collapse.

How much of a fiction that divide really is can be seen in a new report published by academics at the LSE. Is Welfare Reform Working? is based on two rounds of interviews, first in 2013 and again in 2014, with 200 people who live in the south-west of England, from Plymouth to Bath to just outside Chippenham – where Cameron launched his election campaign yesterday.

In my years writing on this subject, I have read scores of reports and books on welfare reform – but I’ve never seen anything like this. Here are hundreds of people, all living at the sharp end of austerity. Every interviewee is a social-housing tenant of working age, which makes them the number one target of this government. Last September Iain Duncan Smith, in an interview with the Express headlined “We are breaking up Shameless housing estates”, boasted: “We’re making real progress into that stubborn part of the out-of-work group who are in housing estates …” The work and pensions secretary was talking about exactly the LSE interviewees – and this report allows them the right of reply: the LSE authors let their subjects do the talking.

The first thing to come screaming out of the report is how many of the interviewees didn’t plan to be out of work. They’ve got a disability, or they were caring for children or a sick parent, or they were just laid off. You meet Mrs Spencer, who spent seven years out of the jobs market to nurse her daughter through cancer. The daughter died two months ago and the last of their savings went on her funeral. Now her husband has been made redundant after 27 years of work. He’s 59 and has only one eye.

'I’ve got a dog and have to make sure he’s OK,' one says cheerfully. 'If need be I’ll eat his biscuits.'

Well over half the respondents claim to be coping. This sounds like good news – until you discover what they mean by that. Getting by means falling behind on rent or into debt; managing means eating less or going without heat. “I’ve got a dog and I’ve got to make sure he’s OK,” one says cheerfully. “If need be I’ll eat his biscuits.”

Re-read that sentence, remembering that you and he live in one of the richest societies on the planet.

How has the government helped? The bedroom tax “is a tax on my disability”, according to one interviewee who used his second bedroom to take oxygen. Respondents hate the jobcentre, which just holds up ever higher hoops to jump through – or else it sanctions them. Another interviewee tells of how his sanction meant that he lost his home, and now sleeps on a sister’s couch.

These people represent a society that has been cut adrift by politicians of all parties: a society that will go unaddressed by the election campaign, and uncourted by any major party. And yet these people talk just like you and me; they just have worse stories to tell.

In that same Express interview, Duncan Smith claimed that he had moved the Shameless estate-dwellers from a “dependency culture” to independence. Here is a different version of events from one of the LSE interviewees: “My best friend committed suicide in March – she went through … relentless reassessments, and found the forms very confusing. She was disabled but they were questioning her over and over again. DWP hounded her for information. It’s a horrible feeling, knowing that your friend was pushed over the edge like that. I’m pretty certain that if these welfare reform changes weren’t going on, I’d still have her with me.”