Dame Kate, a leading economist who last year led a commission of experts examining how to redesign the care system, said she had been brought to tears by the “awful, awful” plight of many of those she met.

But, she warned, the situation is now set to get much worse – and without the prospect of a cap to protect people from catastrophic costs.

Crucially, she warned that, middle class older people in care homes will increasingly be forced to pay extra to subsidise those who cannot pay – something she said was “wrong” and “perverse”.

Using the sick and vulnerable to prop up the system because they are deemed well enough off to pay for themselves, is, she insisted, a long way from David Cameron’s promise that “we’re all in this together”.

The Government’s decision to shelve the long-awaited cap on care bills was, she argued, harder to justify than the Liberal Democrats’ now notorious broken promise to oppose increases in university tuition fees.

Dame Kate’s comments came as the members of her Commission on the Future of Health and Social Care in England, an inquiry backed by the King’s Fund health think-tank, wrote to the Sunday Telegraph urging George Osborne to protect care funding in the forthcoming Spending Review.

“Tackling the deficit does not need to be at the expense of older and disabled people in need of care and support,” they argue.

In a separate paper being published today, they warn that despite recent optimism the care system now seems to be “crumbling around us”.

Currently anyone with assets, including their home, worth more than around £23,250 does not qualify for state support with care.

But reforms passed by the Coalition, based on recommendations by the economist Sir Andrew Dilnot, promised to raise that threshold significantly and cap the amount anyone would have to pay in their lifetime on care at £72,000.

The Conservative election manifesto pledged to implement the cap, promising people it would bring “the dignity and security you deserve in your old age”.

But only two months later ministers signalled that the cap was to be delayed until 2020.

“I just think it is a very striking and early abandonment of something that was clearly in a manifesto,” Dame Kate told the Sunday Telegraph.

She added: “Because the Conservatives were already in government they knew very well what this promise was and how much it cost.

“I do think it is somewhat extraordinary to find that they didn’t realise the implications of trying to introduce Dilnot at a time when social care was otherwise being cut back so heavily.”

The number of people receiving social care in England has fallen by a quarter – or 400,000 – in the last five years at a time when the elderly population has grown by 14 per cent.

Age UK recently calculated that a million people who need help with tasks as basic as washing and dressing are now left to cope on their own.

Dame Kate, a former member of the Bank of England’s Monetary Policy Committee, said the coming years could see increasing numbers denied help altogether and care homes cutting beds.

“I really don’t want to get to the point where this happens because as soon as you start to think about this in personal terms it is so awful,” she said.

“I do feel very strongly about this, it is such a particular group of people – elderly people with dementia, for whom the end of their lives could be very miserable indeed.”

Recent studies have shown that those who do not qualify for state support are being charged up to 50 per cent more in care home fees than their council would pay for the same place for a poorer person – amounting to using frail elderly people to fund the system.

“It seems really wrong for people who have a social care condition to find themselves paying higher fees to subsidise other people,” said Dame Kate.

She added: “I think if you say ‘we’re all in this together’ you don’t mean that people who may not be terribly well off but are well enough off not to have local authority funding are finding themselves the group that are funding the most vulnerable.”

She said she had wept at the plight of some of those her commission spoke to.

“These [are] just awful, awful things that we’re doing to people – and that was before.

“One feels that those cases will get greater and I think then people will start to have an outcry.”

She continued: “I don’t think [people] realise that the collapse of Dilnot and the cuts in local authority social care means that actually for people who can pay the costs may well be higher.

“Maybe that will be the point in which we start to see it, when the penny really drops on that.

“I think we will start to see more of an outcry.”