Nearly 300,000 people are on local authority “waiting lists” for adult social care services in England because of funding pressures and delays in assessments from social workers, according to council care chiefs.

They also revealed that a chronic shortage of care workers meant more than one in 10 people assessed as needing care in their own homes were instead being offered care in residential facilities, often against their wishes.

The emergence of adult social care waiting lists – which have grown by more than a quarter in the past three months – starkly demonstrated the funding and staffing pressures faced by care services, said the Association of Directors of Adult Social Services (Adass).

The figures came as it was revealed some care workers would lose £1,000 a year after the government’s decision to introduce and new healthcare levy and remove the £20 universal credit uplift.

The government has announced a health and care funding plan to raise £12bn a year between 2022-23 and 2024-25, although adult social care is due to receive just £1.8bn of this. The funding boost will be met by an increase in national insurance payments from next April.

Adass says the longer people wait for an assessment the higher the risk that their condition will deteriorate, they will become mentally or physically unwell, they will suffer a fall, or continue to suffer unreported or concealed abuse or neglect.

Although councils have increased the numbers of care hours delivered over the past three months, they have been unable to keep pace with demand because of staff shortages and more people needing care after being discharged from hospital.

Stephen Chandler, the Adass president, said: “This survey is a stark reminder of why we need investment in care and support now. It is neither fair nor acceptable that people are waiting longer and getting less care. People need care and support to live a good life now. They cannot and should not be made to wait.”

A separate analysis by the consultants Policy in Practice found care workers earning the “national living wage” will be more than £1,000 a year out of pocket as a result of the national insurance changes coming in next year to fund the government’s health and care plans, coupled with imminent cuts to universal credit and food and energy price rises.

It calculated care workers earning £9.24 an hour would pay £121 a year to the health and social care levy to fund the care they provide to others. The universal credit changes, due in October, when the £20 a week Covid top-up will be removed, will leave them out of pocket by £1,035 a year, despite increases in the national living wage.

Deven Ghelani, the director of Policy in Practice, said they would be in effect paying for doing their job of caring for others: “That’s the basic unfairness of paying for social insurance through a rise in national insurance while simultaneously taking away support from the lowest earners: those that kept us going through the pandemic are the ones hardest hit.”

The council social care waiting lists indicate the numbers of people who are waiting for an initial care assessment – no care can be given before a formal assessment is made; who are receiving care but are waiting for an annual needs review; and who have been assessed but are waiting for care services to start.

The Adass snap survey carried out in mid-August found people were waiting longer for assessments, were receiving less care and in some cases receiving the wrong type of care and support. About 70,000 people were waiting for an initial assessment, up from 55,000 in May, with 11,000 people waiting more than six months, up from 7,000).

Just over 184,000 people were waiting for reviews of existing care and support plans, up by 15.6% (24,971) compared with May. Under the Care Act councils are legally obliged to review care plans no later than every 12 months. About 19,000 people had been assessed but were waiting for their care package to start.

Adult social care departments have incurred a “deluge” in pent-up demand for care and support after Covid restrictions were eased, but this has been exacerbated by years of austerity cuts, leaving councils unable to tackle staff shortages and having to increasingly ration care.

The Department of Health and Social Care was approached for comment.