There will be posturing.

There will be statistics. There will be anger, real and manufactured. Nevertheless today's Commons debate on capping the level of welfare benefits for the next three years marks a defining moment.

In the blue corner, Work and Pensions Secretary Iain Duncan Smith. who has spent the run-up to this debate telling anyone who'll listen that his Government's welfare reforms are about fairness, backing strivers against scroungers.

In the red, the Labour opposition, wobbling on a self-imposed tightrope between protecting the vulnerable while promising to be tough on reluctant jobseekers.

And, in the middle, the bulk of a bruised and battered British public wondering if there's a chance of a lifeboat any time soon to take them off the SS Austerity and ferry them to something resembling financial security.

If nothing else, this debate has highlighted the value of relentless propaganda. Until now the historical wisdom was that tough times brought a lessening of knee-jerk hostility to people living on benefits.

As more and more people found out the shocking reality of benefit rates for themselves when they lost jobs, it tended to bust the myth that life on the dole was feather-bedded.

Nevertheless a TUC poll last week found a majority of people thought benefits were much higher than they are, and supposed that the fattest chunk of them went on the jobless. It's 3%, as it happens. And, thanks to the relentless reporting of the antics of a few rogue families, respondents supposed more than a quarter of claims were fraudulent. True statistic? 0.7%. Most cash wrongly spent goes not in fraud but department error.

The strategy, says Julian Unwin of the Joseph Rowntree Foundation, seems to have been to create a divide between the poor and the very poor. The foundation has flagged up the astonishing news that for the first time – minus pensioners – there is more poverty among working households than workless ones. So the perceptions found in the TUC poll may alter when the cost of the cap, and all the other cuts due, begin to impact on a much wider spectrum of families.

The Resolution Foundation, an independent number cruncher, has worked out that 60% of those affected will be working people on low incomes. People like single-parent nurses, and soldiers who rely on working family tax credits to keep their heads not very far above water.

Difficult to characterise either as workshy, you might suppose. But then the hallmark of this Coalition has always been a facility to look through the wrong end of the telescope. Consider its plans to cap the total amount of benefits any one family can claim. Sounds perfectly sensible does it not?

It's when you start to unpick it that the logic unravels. The housing benefit bill in places like London has burgeoned largely because unregulated landlords found housing benefit a very profitable way of charging ludicrous amounts for basic property. But rather than crack down on that scam, some councils have deported families to other regions of England distant from schools, families and friends.

Welfare is not a devolved matter, so these are issues which profoundly affect Scotland too.

The Scottish Government, which has just set up a panel to examine "Scottish values" in terms of how welfare should work, has given Scottish councils £40 million to help offset cuts to council tax benefit and put £9m into a crisis fund.

But the scale of hit that families will take can be gauged from the fact that even before today's proposed benefit cap, £2.5 billion will come out of Scottish household incomes thanks to the "reforms" already in place.

According to Rowntree's Julia Unwin, in just eight years' time, one in four families in the UK will be in poverty. That is a truly mind-boggling prospect for a supposedly civilised group of comparatively wealthy nations.

There are other pathways to reform available. Taking many more low-waged people out of tax whilst increasing the rates for those well able to pay more; offering a living rather than a minimum wage to remove more people from benefit need; clawing back aggressively-avoided and evaded tax; addressing the ongoing scandal of obscene bonuses and top executive pay levels.

A successful society can only be built on fairness. To suggest today's proposals are about that is simply disgraceful.