In 1947 the British welfare state was founded on the principle of a contract between workers and the Government.

By paying part of every pay packet into a national fund, employees were purchasing a form of insurance. National Insurance. If they were ever too sick to work, the state would be there for as long as they needed it. In today's labyrinthine network of benefits, this social contract survives in the form of Employment and Support Allowance (ESA). The Coalition Government is about to break that contract by limiting sickness provision for taxpayers to one year, even if the claimant is assessed still as unfit for work.

A report out today from a Scottish cross-party group spells out the far-reaching effects changes to ESA will have on anyone unfortunate enough to fall ill and on the Scottish economy as a whole. The Scottish Local Government Forum Against Poverty calculates the total losses to the country's some 68,000 ESA claimants will be at least £83.5 million. Among those to be summarily stripped of their benefits from April this year will be cancer patients, those with multiple sclerosis, diabetics and people with psychiatric conditions. Their best hope lies with the House of Lords where a group of mainly Labour and Cross-bench peers will attempt to curb the worst excesses of the Welfare Reform Bill today.

If they fail, after 365 days the benefit will be means tested so that modest savings or a partner earning as little as £149 a week will result in their income being cut or disappearing altogether. This is the result of a tax system that treats people as individuals while the benefits system is based on household income. In fact, one consequence of this change may be to force couples apart.

Another effect could be the revival of private insurance, hot on the heels of the scandal over the mis-selling of personal protection insurance and the payment of more than £1 billion in compensation to victims.

As the report observes, these changes will put extra pressure on local authorities at the very time they are struggling with diminishing budgets, raising the issue of whether Scotland's Council Tax freeze is sustainable. Something has to give, or scandalous stories of the very sick being forced out to work or into dire poverty will soon start to emerge.

It is hard to resist the conclusion that the Coalition has cynically decided to pick off marginalised groups that do not have a loud voice. (Compare the muted campaign for ESA to the hullaballoo about middle-income families losing Child Benefit.) Such is the complexity of the welfare system and the scale of the revolution being pushed through that it is hard to focus on one particular benefit or group. To add insult to injury, many of those households losing ESA will also be losing housing benefit and tax credits.

A largely unchallenged Coalition narrative about the UK economy on the verge of Greek-style meltdown and weighed down by scroungers and malingerers softened up a gullible electorate for £18bn of welfare cuts. It is only when hard-working relatives are struck down by cancer or brave victims of workplace accidents have the rug pulled from under them that the reality of these changes become clear. Why is Nick Clegg allowing this to happen in his name?