What are the limits of people's choice and control over their care and support? Should there be any? Or does the state have a duty to ensure that risks are minimised and taxpayers' money is used appropriately?

The principle of personalisation is now embedded in the care system, at least in England. But there is continuing uncertainty over how far it should be taken, as illustrated by a dispute between a council and a disabled young man who wants to use his direct payments to employ his mother for 76 hours a week for his care and for support with social activities.

Under national guidance (pdf), councils may "where necessary" allow recipients of direct payments to employ a family member living in the same home as their personal assistant (PA). After a long wrangle, the council in this case, Cheshire East, has conceded the point but is balking at the payment of one individual for as many as 76 hours - twice the length of a typical working week and worth a weekly wage of almost £800.

The local government ombudsman (LGO) has now ruled that Cheshire East has been wrong to cite working time regulations, which limit the average working week to 48 hours but which offer the employee an opt-out. It has told the council to reconsider the matter, "balancing choice and risk".

The family involved in the case is not being identified. The young man suffered a serious spinal injury while playing sport at university in September 2013. His mother, a lone parent, then gave up her job to become his carer.

A key incident in the case occurred soon after the young man was discharged from hospital three months later. On a night out with friends, he was highly embarrassed to run into a care worker who was giving him reablement support at home. After this, he became reluctant to have care workers attending to his needs.

Those needs were formally assessed by the council in May 2014 as requiring 56 hours a week care - including washing, dressing, help with continence and one hour of support during the night. In June, the assessment was amended to include a further 20 hours for sport and leisure activities.

It was not until August last year, by which time the family was struggling financially, that the council agreed that the mother could be employed as a PA. But it insisted she could not exceed the hours stipulated in the working time regulations. By this stage the family had complained to the LGO and it was only after repeated interventions by the ombudsman's team that the first direct payments, based on a 48-hour week, were made in October.

The ombudsman, Jane Martin, says in her ruling that Cheshire East should not have applied the working time regulations because the mother had made clear she wished to opt out. If it continues to argue against her employment for more than 48 hours on grounds of risk, it must conduct a proper assessment of the number of hours she can "safely and sustainably" provide.

Pending such an assessment, Martin has told the council to pay the full 76 hours backdated to January 2014, worth £788.88 a week at an hourly rate of £10.38, and to award the mother a total £350 compensation and her son £250.

Finding that Cheshire East has caused the family distress, financial problems and uncertainty, the ombudsman warns: "Councils must properly consider individual circumstances when they balance people's choice to be cared for by a family member against the risk to their carer of working long hours."

Many unpaid carers will be all too familiar with working long hours. According to charity Carers UK, more than 1.3 million people provide in excess of 50 hours of care a week to a family member or friend.

Far fewer families are eligible for the kind of funding in the Cheshire East case. But the In Control network, which promotes take-up of direct payments (of which about £1.5bn are now made annually in England), reports rising numbers of calls to its helpline from people who are considering employing a family member as a PA, though it says it is still "fairly rare" for that person to be living under the same roof.

Official guidance under last year's Care Act states: "In certain circumstances (ie where it considers it necessary to do so), a council may allow people to use direct payments to secure services of a family member with whom they live. However, it is for local authority discretion as to what determines such cirumstances, and this should take into account the needs of the person and their family, and the outcomes the person wishes to achieve."

As an example, the guidance gives the case of someone with a severe learning disability who has "serious trust issues and a unique way of communicating that only his family, through years of care as a child, can understand".

Cheshire East says it accepts the ombudsman's rulings, apologises to the family and acknowledges that there were unacceptable delays in the case and that the needs assessment process was "not as robust or as comprehensive as it should have been".

Mike Suarez, the council's chief executive, says: "The findings of the LGO are being taken very seriously by the council, and acted upon with urgency, and all areas will be reviewed. The council will continue to work with this gentleman and his family to ensure that his needs are appropriately met and that he is supported to lead as independent a life as possible."