Vulnerable and elderly people in Birmingham face a huge increase in the cost of home care services in an attempt to plug a city council cash crisis.

The existing maximum £100 a week charge for social services provision – however complex the care package – is to be scrapped. Anyone with savings of more than £22,250 will pay the full cost of their care as a result of the change.

The decision is expected to taken by the council cabinet in the next few weeks following mounting evidence of a severe financial drain on the Adults and Communities budget, which is heading for a £9 million overspend.

Most of the overspending stems from increased demand for the Learning Disability Service, which has seen its costs soar from £9 million a year in 2006/07 to almost £51 million a year now.

But the true extent of problem is masked by the continuing difficulty of recruiting social workers.

The council has almost 150 social worker vacancies, more than 25 per cent of the total staffing establishment.

If the council managed to fill all vacant social worker posts, it would be able to save the money it currently spends on hiring expensive agency staff.

The cost of placing children in care continues to pose problems in Birmingham, following a £3.8 million budget overspend last year. More than 2,000 children are either with foster parents or in residential homes, at an average annual cost of £44,000 per child.

A cabinet briefing report says that extra demand for Learning Disability services is being driven by improved medical treatment for disability.

Requests for help have also risen following the opening of the council’s one-stop telephone contact centre, making it easier for the public to get information about social care provision.

About £30 million of the total Learning Disability expenditure is tied up in weekly aid packages costing more than £1,000 per person. Cabinet members are be asked to support further talks over how the cost of caring for disabled adults and children should be divided between the council and the NHS.

The report adds: “Resources are not being used effectively across the whole system. We are seeking to avoid a traditional boundary dispute across health and care, but must see a robust and overdue discussion about the use of all available health care and personal resources. The overall funding allocation to Learning Disability is generous when compared to other authorities.”

A spokeswoman said the council was moving away from the “outdated ‘one size fits all’ care model” and helping people remain independent for as long as possible.

She added: “In line with many local authorities, a £100 cap on non-residential services, particularly for those with significant resources, is no longer supportable. The financial cap can distort the fairness of charging as it puts a ceiling on the amount charged, regardless of a person’s ability to pay.”