Mmental health services throughout Sussex are coming closer to being run by a single county-wide trust.

The new Sussex Partnership NHS Trust would be responsible for all mental health, specialist learning disability and substance misuse facilities for a population of more than one million.

Surrey and Sussex Strategic Health Authority is expected to give the go-ahead to the plans at a board meeting next week.

The changes will mean the merger of East Sussex County Healthcare and West Sussex Health and Social Care NHS trusts.

South Downs Health, which is responsible for Brighton and Hove, will transfer most of the services it provides to the new trust.

A decision has not been made yet on how South Downs' community, rehabilitation and children's services, which will not be part of the new trust, will be managed in the future. The decision to press ahead with the merger follows a public consultation on the future of mental health services across Sussex.

South Downs said it wanted to stay independent and work more closely with Brighton and Hove City Council and the local primary care trust (PCT).

Mental health needs in the city are 40 per cent greater than those of West Sussex and 33 per cent greater than East Sussex.

The city also has one of the highest drug-related death rates in the country and the trust felt decision-making and control of budgets should be kept local.

The trust was supported by the independent watchdog The Patient And Public Involvement Forum and Brighton Pavilion MP David Lepper. Those in favour of the merger said it would mean less red tape and make services run more smoothly.

Clive Evans, chairman of the steering group which studied the responses to the consultation and made the recommendation for the merger, said: "There was no clearly favoured option for configuration of the specialist NHS trusts.

"Generally, the public, service users and carers and non-statutory organisations were much less interested in which organisation provides services and much more in how, where and when services were provided.