The explosion in charities, voluntary organisations and social enterprises providing services to the NHS and social care looks set to overlook mental health, a survey has found.

The Third Sector Market Mapping Research Report, prepared for the Department of Health by IFF Research, surveyed charities and other organisations to gauge plans for future involvement in the provision of health services.

It found that third-sector organisations believe they will grow their business by£1bn next year alone, but only 8 per cent of those planning to deliver services in the next three to five years wanted to deal with mental health.

Mental health patients are currently the biggest client group in third-sector health, but organisations involved in the field worried that funding levels for mental health would make provision of services more difficult.

Only one local authority said it planned to increase mental health funding, while others planned to reduce funding by up to 80 per cent.

Mental health charity Rethink chief executive Paul Jenkins agreed this was a problem: 'We need long-term commitment to contracts rather than a fair-weather approach to funding where there may be a retraction if times are hard.

'For small organisations, a stop-start approach is life-threatening.

'People are under greater financial pressures but commissioners have got to treat the third sector as they would the public and private sectors.'

The report found that the potential and scale of third-sector provision of health and social care was significant. Half of the third-sector organisations questioned felt there were services they could deliver more effectively than current providers, and 89 per cent said they could provide more services than they currently do if the demand and funding existed.

Of organisations not currently providing services, an estimated 1,600 expect to do so in the next three to five years, the report found.

Of these, 17 per cent said they intended to provide only healthcare services, and 22 per cent said they would offer both healthcare and social care provision.

The survey found that only 1 per cent of organisations were averse to providing services in the future.

The results will be used by the DoH's third-sector commissioning task force, set up in 2005 to help boost the sector's profile in delivering services.