Costs of adult social care have become “insurmountable” following the “catastrophic impacts” of the Budget, a leading voice in the sector will tell a conference featuring the care minister.

Local authorities in England could face extra costs of an estimated £1.8 billion as a result of a rise in national insurance contributions (NICs) and wage bills for providers, the Association of Directors of Adult Social Services (Adass) was expected to hear.

President Melanie Williams said this does not include the cost to the wider social care sector such as overall increased demand from people needing more complex care.

Opening the national children and adult services conference (NCASC) in Liverpool on Wednesday, she was expected to say: “We cannot vision for a tomorrow when the cost of today has become so insurmountable. The Budget had catastrophic impacts on the cost of adult social care.”

Care minister Stephen Kinnock is due to address the conference on Thursday.

The sector has been roundly critical of last month’s Budget announcements, saying the £600 million for social care will be dwarfed by the costs from the NIC and wage rises.

Chancellor Rachel Reeves increased the rate of employers’ NICs by 1.2 percentage points to 15% and slashed the threshold at which the tax starts being paid from £9,100 to £5,000 to raise £26 billion a year.

She also announced that the national living wage will increase by 6.7% for employees aged 21 or older – from £11.44 an hour to £12.21 – from April.

Adass said it estimated the effects could cost councils about £1.2 billion in inflationary pressures and a further £0.6 billion in the cost of provider fees paid by councils.

Ms Williams will say: “Quite frankly, if adult social care had almost £2 billion spare, we would be implementing charging reform and building a really decent early help and prevention service in all of our places.

“Should we end up having to give a big chunk of this money to Government, the consequences are unimaginable on our ability to meet need.”

Ms Williams said she was “delighted” to welcome Mr Kinnock to the conference, praising the acknowledgement of “the value” of adult social care she said he and Health Secretary Wes Streeting had made since taking up their roles this summer.

“We welcome this acknowledgement and that they see the health mission as one of economic growth and investment,” she said.

Care minister Stephen Kinnock walks down a street in London
Care minister Stephen Kinnock is due to address the conference on Thursday (Stefan Rousseau/PA)

Adass said possible ways to alleviate the impacts could be to delay the implementation of the increases, lower the rates, exempt providers or pay councils compensation.

Separate analysis last week by the Nuffield Trust, which focused on non-local government services, estimated private and non-profit social care providers could be faced with increased costs of about £2.8 billion in the next financial year.

The health and social care think tank’s analysis said the NICs and wage bill rises for providers could see “swathes of the social care market collapsing under these extra cost pressures”.

Meanwhile, a survey by the Care Provider Alliance (CPA) of more than 1,180 care and support providers in England found 22% of those asked said they were planning to close their businesses entirely and 57% will hand back existing contracts to local authorities or the NHS as a result of the rising costs.

Almost three-quarters (73%) said they will have to refuse new care packages from local authorities or the NHS, and 64% said they will have to make staff redundant.

The Government has repeated its case that it “inherited a social care system in crisis” and remains “determined to tackle the significant challenges and build a national care service so everybody can access the high-quality care they deserve”.

The conference, jointly organised by Adass, the Association of Directors of Children Services (ADCS) and the Local Government Association (LGA), will also hear of a likely growing need for children’s social care workers in the coming years without more investment in early preventative services.

The LGA said the number employed by councils will need to increase by 13,000, which it said is almost a third on current levels, over the next decade.

Almost 46,000 could be needed by 2034, the LGA said, putting this down to a rising need among children for care and support.

Arooj Shah, chairwoman of the LGA’s children and young people board, said: “It is vital we invest in early help and support so that fewer children and families see their needs escalating and requiring support from children’s social care.

“Without this investment, there will need to be thousands of additional children and family social workers hired over the next decade.”