Protests grew yesterday at the Government's failure to tackle the scandal of mixed-sex wards as a new report warned that women and young people with mental problems were at particular risk.

Two days after the Health minister Lord Darzi admitted that eradicating mixed-sex wards was "an aspiration that cannot be met", the Mental Health Act Commission expressed "serious concern" about the safety of vulnerable patients detained on mixed-sex wards for psychiatric care.

NHS patients are continuing to suffer the indignity and embarrassment of being cared for on a ward shared with members of the opposite sex more than a decade after the Government pledged to abolish the practice. One patient in 10 is still looked after on a mixed-sex ward, compromising dignity and adding to the stress of illness. Many are forced to share bathrooms and lavatories and almost a third of emergency patients have to share a sleeping area on admission.

The Mental Health Act Commission found that many psychiatric wards especially in London and big cities were overcrowded, with more than a third having occupancy levels above 100 per cent. Many of the 6,000 patients interviewed over two years found their hospital stay frightening.

Professor Chris Heginbotham, chief executive of the commission, said: "Patients admitted to hospital under compulsory powers should be able to expect that they will be cared for in a safe and welcoming environment. Sadly this is too often not the case."

The findings echo a report in 2006 by the National Patient Safety Agency which said there had been 19 suspected rapes and more than 100 incidents of sexual assault on mental health wards in two years. A survey published last year by the Healthcare Commission found 55 per cent of patients in mental hospitals were in mixed-sex accommodation.

Tony Blair said in a speech in 1996, when leader of the Opposition, that it should not be "beyond the collective wit of government and health administrators" to eliminate mixed-sex wards from the NHS.

Yet despite government pledges in the 1997 and 2001 manifestos, the problem remains. A target set in 2000 to eliminate mixed-sex wards in almost all health authorities by the end of 2002 was missed and the date extended to 2004.

By 2006, the Department of Health was claiming 99 per cent of patients were treated in single-sex "accommodation", a subtle change from its earlier pledge to provide single-sex "wards". But when the Independent columnist Janet Street-Porter movingly described the indignity suffered by her sister, Patricia Balsom, in a mixed-sex ward as she was dying of cancer, it unleashed a flood of protests by patients with similar experiences.

Forced on to the defensive, Patricia Hewitt, who was Health Secretary, ordered an inquiry which confirmed how far claims by NHS trusts failed to tally with what patients were experiencing. This was because some trusts designated bays within wards as single sex, even when they were only separated by a curtain.

The inquiry report, by the chief nursing officer, Christine Beasley, published last May, found one in five trusts was still resorting to mixed-sex accommodation.

It was the failure to distinguish mixed-sex wards from mixed-sex accommodation that got Lord Darzi into hot water this week. As an experienced surgeon but political ingénue – he was appointed to the Government last summer – he admitted that to accommodate every patient on single-sex wards would require rebuilding of the NHS.

He went on to say, in his remarks in the Lords, that the Government was still committed to single-sex accommodation – single-sex bays or rooms within wards – but this was interpreted to mean that men and women could be separated by no more than a curtain.

The Department of Health has strengthened its definition of single-sex accommodation by outlawing the use of curtains as dividers and insisting that bays should be split with "full height, rigid, fixed partitions". Full height, however, does not mean necessarily fixed to the ceiling but high enough to "ensure that patients perceive they are in a separate room". Emergencies may still be admitted to mixed-sex wards.

Ivan Lewis, a Health minister, said yesterday that "good progress" had been made on mixed-sex accommodation. "But we know there is more to do. We have asked strategic health authorities to publish statements setting out the progress they are making."

Jenny Morgan, 56: 'I was horrified'

Jenny Morgan was waiting to go into Solihull Hospital for a knee operation when she received a letter saying she would be staying on a mixed-sex ward. She was uneasy about the news.

"I knew I'd be pretty immobile and that I'd have to use a bedpan, so I wasn't sure I'd want to share a ward with men", she said. And when the hospital offered her the chance to look round the ward to help make up her mind, she accepted

the offer. "They said it would reassure me" said Ms Morgan, "but I was horrified. They had single-sex bays separated by curtains, but they were really flimsy."

On the strength of that visit, Ms Morgan has decided to get the operation done privately. She said: "My knee was painful, but I thought it wasn't worth the embarrassment."

Anthea Frost, 61: 'I pleaded to be taken off the ward'

Anthea Frost was shocked when she was admitted to the Princess Royal Hospital, Telford, with crippling stomach pain from a gallstone in December.

"I found I was the only woman in a ward full of men. The chap opposite had no top on and his pyjamas were gaping open. They were all passing wind as men do. I hadno warning when I was taken in through A&E. It was very distressing."

Within 24 hours she had discharged herself and used a small inheritance from her mother to pay privately for her treatment – an operation to remove her gallbladder – at a cost of more than £5,000.

"I pleaded with them to take me off the ward – I even offered to pay to go into the private ward – but they said there were no beds. I could have coped if there had been some other women with me but to be on my own with all those men was too much."

Ms Frost, a former health adviser who worked with HIV patients, added: "I worked for the NHS for 30 years but when I needed it, it was not there for me."