Peers including former Conservative and Labour chancellors have called for an immediate £8bn investment to tackle the “national scandal” that has left over a million vulnerable older people without proper social care support.

The Lords economic affairs committee said this would restore access and quality of social care services in England to pre-austerity levels and relieve unsustainable pressure on unpaid family carers. A further £7bn a year should be spent to extend NHS-style free personal care to all by 2025, to be paid for out of general taxation.

The chair of the cross-party committee, Lord Forsyth, said it was time for government to stop “faffing around” and properly fund a system that was riddled with unfairness and left people enduring real suffering. “Our recommendations will cost money, but social care should be a public spending priority,” he said.

The committee’s report comes amid growing concern at the state of adult social care after a decade of austerity. The outgoing Tory chair of the Local Government Association, Lord Porter, recently warned that vulnerable people would die as a result of the continuing failure to properly fund social care.

Forsyth, a former Conservative government minister, told the Guardian the fairest and most efficient way to meet the £15bn cost was via taxation. “I’m a Thatcherite Tory: I support reducing tax and controlling public expenditure. But this is the minimum requirement to provide a decent standard of care in our country.”

The committee said 1.4m older people were denied the care they needed as a result of cuts, means tests and rationing, while others received extremely basic “clean and feed” levels of care. Many as a result were housebound and unable to fulfil everyday tasks like washing or going to the toilet.

With growing demographic pressures – by 2040 a quarter of the UK population will be over 65 and there will be thousands more working age adults with severe disabilities – social care funding reform was an urgent priority, the committee said.

At least 17 white papers, green papers and official reviews of social care funding have been published in the past 20 years, the committee estimates, none of which have led to meaningful reform. The latest promised government green paper has been delayed at least six times over the last 18 months.

The committee questioned the point of publishing yet another report. “Let’s not have a green paper,” said Forsyth. “If you have to, have a white paper, and write a cheque to the local authorities. Let’s stop faffing around and get on and do it.”

Politicians had been too quick to denigrate proposed changes as a “death tax” or a “dementia tax” to gain electoral advantage, thwarting reform, the report said, adding that there must be cross-party agreement on a way forward on adult social care and have an honest conversation with voters about how it is to be paid for.

Social care surfaced in the Tory leadership contest when Jeremy Hunt – a former health and social care secretary – admitted cuts had gone too far. While Hunt and rival Boris Johnson have pledged tens of billions in public spending, neither has mentioned social care.

The committee’s members include former Labour chancellor Lord Darling, former Tory chancellor Lord Lamont, former Treasury permanent secretary Lord Burns, ex-cabinet secretary Lord Turnbull and former Talk Talk boss Lady Harding.

Free personal care was introduced for over-65’s in Scotland in 2002, giving recipients help with daily tasks such as bathing, dressing, personal hygiene, going to the toilet, and meal preparation. Numbers of people receiving care doubled as a result, but it ultimately saved taxpayers’ money by preventing costly hospital admissions.

However, free personal care should not include the costs of accommodation, which would be met as now by the individual, the committee said, but government should explore introducing a cap on individuals’ financial liability.

Without urgent action to address social care funding, much of the burden of caring for vulnerable individuals would continue to fall on family and friends. Most unpaid carers were women, the report said, with 63% of female carers aged between 50 and 64 caring for at least 50 hours a week.

A Department of Health and Social Care spokesperson said: “We have given local authorities access to up to £3.9bn more dedicated funding for adult social care this year, and a further £410m is available for adults and children’s services. We will set out our plans to reform the social care system at the earliest opportunity to ensure it is sustainable for the future.”