The standard of mental health service in England is 'unacceptable', care minister and North Norfolk MP Norman Lamb has admitted.

His admission comes as a leading psychiatrist described the service as in 'crisis' and new figures reported by the BBC showed that many trusts are running at full capacity.

More than 1,500 mental health beds have been closed since April 2011, representing a reduction of 9pc, an investigation found.

Mr Lamb told the broadcaster the current situation was 'unacceptable' and provision must improve.

Freedom of Information requests were sent to 53 of England's 58 mental health trusts by BBC News and Community Care magazine, and 46 trusts replied.

Three-quarters of the 1,711 bed closures were in acute adult wards, older people's wards and psychiatric intensive care units.

Average occupancy levels in acute adult and psychiatric beds are running at 100%, while half are over that and all are above the 85pc limit recommended by the Royal College of Psychiatrists.

The Norfolk and Suffolk NHS Foundation Trust reported a 35-bed reduction since 2011 and that its adult pshyciatric occupancy was running above 100pc - but all other departments ran below 100pc.

Andrew Hopkins, acting chief executive of the Norfolk and Suffolk Trust, said 'The trust welcome's the Minister's commitment to address the institutional bias against mental health provision in the NHS.

'At a time when the amount of money mental health trusts receive is reducing in real terms, and demand for services is increasing, services are placed under a lot of pressure.

'Norfolk and Suffolk NHS Foundation Trust's acute inpatient services compare favourably with national benchmarks for quality and efficiency, and compared to many other Trusts a small number of service users are placed in out of area beds.

'Today, for example, four people receiving care from the Trust are in out of area placements. Whilst this remains a serious concern, and something we are working to address, it reflects the fact that demand for beds is currently higher than in previous years, in Norfolk and Suffolk as well as the rest of the country.

'Much has been done to avoid the need to admit people to hospital and care for them in their own homes, where many people would prefer to remain, such as increasing Home Treatment teams, but sometimes there is no safe alternative to an admission. When demand for our own beds outstrips supply, we have to find a suitable bed elsewhere.

'We continually lobby our commissioners for more investment in mental health services, rather than the current budget reductions that are being imposed on the Trust, and would welcome any additional funding for acute services.'

Psychiatrist Dr Martin Baggaley, medical director of the South London and Maudsley NHS Trust, told the BBC: 'We are in a real crisis at the moment. I think currently the system is inefficient, unsafe.

'We're certainly feeling it on the front line, it's very pressured, and we spend a lot of our time struggling to find beds, sending people across the country which is really not what I want to do.'

At the time of speaking he said he had 50 patients in beds outside his trust, including some in Somerset, and that no beds were available in London.

Mr Lamb added: 'Current levels of access to mental health treatment are unacceptable. There is an institutional bias in the NHS against mental health and I am determined to end this.

'More people are being treated in the right settings for them, including fewer people needing to go into hospitals. It is essential that people get the treatment they need early and in the community but beds must be available if patients need them.'