Amid recession, austerity and the problematic politics of coalition, the climate is hardly propitious for a massive overhaul of care for the elderly and disabled. But overhaul it we must and time is running out. Tricky or not, the challenge is one to which politicians across the spectrum must rise.

There are two problems to address. One is that existing standards of care are patchy, at best, and the means-tested system for looking after the less well-off is routinely described as "broken" by experts in the field. No less alarmingly, demographic changes are expected to add, within 20 years, another two million to the number of people needing care. After successive abortive attempts to grapple with the question of how it will all be paid for – and how to avert the threat of the old and infirm forced to sell their homes to pay for their care – radical reform is an issue that can no longer be ducked.

After a promising start, however, that appears to be exactly what the Government is doing. The original plan was for research commissioned in the Coalition's first parliament to be followed up with the necessary legislation in the second. But this week's Queen's Speech promised only that a Bill to modernise social care will be drafted by ministers in the new session, and it will not reach Parliament until the next one, in 2013. More worrying still, there is no sign of the detailed policy document expected from the Department of Health, compounding fears that any reforms will not go far enough.

The central problems are, perhaps unsurprisingly, money and politics. There is a broad consensus behind the main proposals of the Dilnot review – that the threshold above which individuals must contribute to the cost of their care should go up from £23,250 to £100,000, and that the total costs any individual will have to pay should be capped, possibly at around £35,000. But attempts to establish a similar consensus on how to pay the £1.7bn price tag have made little progress.

It is not acceptable to let the matter slide. Mr Dilnot's plans have much to recommend them. They not only address concerns about old people forced out of their homes. By limiting liabilities for the first time, they will also help create a market for insurance to help defray the risks further.

In a time of austerity, there are few areas which merit extra spending. This is one them. Finding the money for the Dilnot proposals should be near the top of the Chancellor's priorities, even if it means looking at political shibboleths such as pensioners' free bus passes. And it is up to the Opposition to eschew petty politics and do all they can to help.

Future funding is only one part of the problem, however. And it must not distract attention from the equally pressing difficulties of the here and now. Only this week, an open letter signed by 85 care groups warned that the elderly and disabled face "misery and fear" as a system designed in the 1940s struggles to cope.

Even without Dilnot, there is no avoiding the fact that social care needs more money. Funding has increased at a fraction of the rate of the overall NHS budget in recent years, even as the number of people requiring care has carried on rising. More importantly still, the system needs radical reform. That means better preventative measures, an end to purely functional "flying visits", and, above all, closer integration between the social care system and the NHS.

Social care is one of the most intractable problems Britain faces. There are no easy answers, particularly not with money so tight. But after more than 15 years of procrastination, postponement, and failures of political courage, the time for excuses has run out. The Prime Minister cannot tackle the issue single-handedly. But he can achieve much by taking a high-profile lead. He must do so.