The Court of Appeal has committed the taxpayer to a hefty bill for wages it says are due to a group of workers for time spent sleeping. The workers, carers for people with disabilities, are on call while they sleep, and have been paid an overnight allowance that falls well short of the legal minimum wage on an hourly basis.

The ruling is expected to cost the Health Ministry $360 million in back payments and add $50 million a year to the costs of disability support services. State Services Minister Tony Ryall says the court's ruling could also apply to the likes of teachers who sleep overnight on school camps and staff in Child Youth and Family homes. With the minimum hourly wage soon to rise to $13, the implications for the public accounts will be significant unless the Government legislates to change minimum wage calculations.

Mr Ryall has hinted that it might, noting that the court pointed out the existing legislation was based on work definitions from 1945. He seems to think few people at that time worked outside the hours of nine to five, but shift work has always been a fact of life and the same issues have arisen for emergency services such as fire crew who can sleep on night duty.

The question has arisen for services to the mentally disabled only since their care was moved out of institutions and into the community. The extra costs of supervision in ordinary suburban homes was of little concern beside the virtues of providing a more normal home life. It seemed to be assumed that dedicated carers would do rostered overnight stays for nominal extra payment.

The carer who brought the test case is paid $34 for an overnight stay plus $17.66 an hour for any time he spends attending to the residents in his care. If he is not woken during the night his flat allowance amounts to $3 or $4 an hour. He thinks he deserves the $12.50 statutory minimum rate just for being present, and it is hard to argue with that.

He is not in his own home, he is not free to leave, he is responsible all night for the safety of the residents and obliged to see to their needs at any time they arise. His overnight presence is essential to his employer's business. It should be properly paid.

But if community care is going to remain affordable for the taxpayer, something less than the statutory minimum needs to be negotiated for sleeping time. The carers' union appears to recognise that; Labour's spokeswoman, Darien Fenton, said the Government had spurned several opportunities to negotiate a settlement.

Now the Government has three options. It can legislate, negotiate or appeal to the Supreme Court. The case has succeeded in the Employment Court and the Court of Appeal, it is unlikely to fail at a third. Legislation would be fraught, particularly if it adopted a proposition rejected by the court, that the minimum hourly wage should be an average over a working period, not a requirement for every hour at work.

That is a proposal unions would not accept generally but could accept in a specific negotiation. Fire service unions have negotiated contracts for time packages that include rostered overnight duty but not at an hourly rate. Some such salary arrangement for community house minders would seem the best answer.

It is hard to see that the implications of the ruling are as wide as the minister fears. State servants already on salaries, such as teachers, would surely not claim an hourly rate for the occasional overnight duty. Professionalism should come into play.

Supervised community houses were always likely to be an expensive proposition. Supervisors should be as anxious as the Government to see that the cost does not put community care at risk.