I saw my mum forced to fight and cajole as a carer. When will politicians end the conspiracy of silence on adult social care? | Rory Kinnear

My sister, Karina, suffered a lack of oxygen at birth causing her to have multiple complex health problems. For most of her life, after my father's death, my mother was her sole carer.

During that time, Mum argued and fought and shouted and cajoled and wrote and championed and filled-in-forms and coerced and harassed and endured and chivvied and filled-in-different-forms-after-the-old-forms-had-been-changed and phoned and met and refused-to-accept and lobbied and advocated and relentlessly struggled her way to as good an area-health-authority care package as she could get.

But however hard she pushed she would always hit a wall. Thousands of families across the UK will know the feeling: bumping up against the predetermined line where governments hope love will cover the shortfall.

And yes, love – parental, filial, familial – is extraordinarily resilient. It can survive loss of happiness, the diminution of self, a squeezing of ambition, the fracturing of family, the destruction of personal finances, a reduction in physical capacity and much more. It is endlessly elastic. But should love's resilience really be so voraciously exploited, and at such cost to people's lives?

Judging from the main two parties' approaches to adult social care, they seem to believe that it should be. Extraordinarily, despite the 5 million unpaid carers in England and Wales, their nearly 5m votes, their nearly 5m voices, Labour and the Conservatives are still not talking in any meaningful way about adult social care. Or thinking about it, if the woolliness of their manifesto commitments are to be believed.

The most striking absences in both parties' manifestos is the lack of detailed, costed plans for social care. Labour's proposal of a national care service and a fair-pay agreement are welcomed, but when will this happen? Carers are in crisis now. While lofty promises and ambitious goals are admirable, they ring hollow without a clear financial framework .

The Tories, meanwhile, plan on introducing a multi-year funding settlement to local authorities and a cap on costs from October 2025. However, in an 80-page manifesto bursting with policies and promises, social care is given just two measly paragraphs. Blink and you might miss it. In both cases, the silence on support for unpaid carers is deafening.

A democratic election should be a great leveller for a nation. For one day each of its members is, in theory, granted equal status: one vote, as equal in weight and power as the next person's. And yet time and time again, from one electoral cycle to the next, I have marvelled at an inexplicable political embargo on the subject and a profound lack of empathy for those living through the crises in the sector.

Many thought the New Labour government could transform social care; promises were made by David Cameron; Theresa May advocated for the "dementia tax" to fund social care only to U-turn; and Boris Johnson declared he would " fix the crisis in social care once and for all". The reality, however, is that for the past few decades, the story has been one of disappointment. The result: disabled adults and their carers are still struggling to fund basic daily needs, and in many cases going years without a break.

Recent discussions with the national charity Revitalise , which I have supported over the years, have demonstrated to me the magnitude of the crisis. Its Give me a Break campaign has revealed that only one in 129 unpaid carers in England are receiving respite support. Not only that, but carers are even being denied financial support by local authorities, a direct unlawful breach of the 2014 Care Act.

Disabled people and their carers have been abandoned by politicians and policymakers for decades, and they are at breaking point. The system is broken, and that needs to be admitted if it is to change. There is a gargantuan social care funding challenge. Successive governments have kicked the can down the road, unwilling to confront the reality of the problem's scale. And now another election rolls around with a selection of manifestos, most of which lack any ambition to rectify the crisis. Has it already been decided that the UK still cannot afford to prioritise social care? At what cost? Do we really consider the dignity and quality of life of disabled people and their carers so disposable?

One vote, equal in weight, for all. A fair system, for one day. Wouldn't it be miraculous if whoever finds themselves our prime minister on 5 July wanted to extend that sense of fairness for longer? Maybe they will tackle the crisis in adult social care with the same passion and pride that is often afforded the NHS. It will be no small feat to reverse decades of government neglect in this particular sector, I know, and I'm aware that other sectors are also crying out for reform. But what is a moment of opportunity, of possible change, if not a moment to hope?