Hospitals will face fines if they fail to end the "indignity" of mixed-sex wards, Health Secretary Andrew Lansley said today.
From January, hospitals in England will be required to place all patients in single-sex accommodation - with any breaches made public and financial penalties imposed.
Only accident and emergency and intensive care wards will be exempt from the new regulations, Mr Lansley said, unless there was "compelling clinical justification".
"It should be more than an expectation, it should be a requirement that patients who are admitted should be admitted to single-sex accommodation," the Health Secretary told BBC Radio 4's PM programme.
"Patients should be in single-sex accommodation, meaning that all of their period that they are admitted they should be in a bed or a bay which only consists of people of the same sex.
"And they should be able to come and go, for example to all their washing and toilet facilities, without having to pass through a part of the ward or another ward where there might be people of a different sex... so to that extent they would have the kind of privacy and dignity people have a right to expect."
While some hospitals had already declared they had "virtually eliminated" mixed-sex wards, Mr Lansley said there were in fact "thousands of breaches" across the country.
Figures released by the Department of Health showed that in the first quarter of 2010-11, NHS organisations reported 8,028 breaches where patients were accommodated in mixed-sex accommodation without clinical justification
The data was collected from half of England's Strategic Health Authorities. If the same level of reporting existed across the remaining Strategic Health Authorities, it suggests that, across England, there were at least 16,000 breaches in the first quarter alone - and more than 64,000 every year.
"That is not acceptable, so what I will be looking for from the end of this year is a system by which we are very clear that the requirement is that patients should be admitted to single-sex accommodation," Mr Lansley said.
"As part of our overall system of payment - which will be geared towards quality, rewarding quality and penalising for failures to meet essential standards - hospitals will be required to meet that standard, and from January hospitals will be required also to report that they have admitted patients to single-sex accommodation or if they haven't, how often they haven't and why they haven't."
Such publication would "empower patients" through good information, Mr Lansley said, ending a system where they could not find out how often patients had been put into mixed-sex wards.
And he added: "Patients should not suffer the indignity of being cared for in mixed-sex accommodation. I am determined to put an end to this practice, where it is not clinically justified."
Chief Nursing Officer Christine Beasley welcomed the move.
"Protecting the privacy and dignity of patients by eliminating mixed-sex accommodation must be a priority for the NHS," she said.
"Driving this change will be the publishing of statistics on mixed-sex accommodation breaches by NHS Trusts. This measure will allow patients to make better informed decisions about their care."
But Jo Webber, deputy policy director of the NHS Confederation which represents over 95% of NHS organisations, said: "The NHS has already made a great deal of progress on eliminating mixed-sex accommodation and we know this is something patients and the public value.
"A large number of the facilities which still need to be changed are old building stock and will need substantial re-investment in order to meet this target.
"There will sometimes be circumstances when it is in the interest of the patients to treat first and worry about the suitability of accommodation later. We should also recognise that, to ensure dignity in care, other factors such as organisational culture and training are just as important as providing single-sex accommodation."
If Mr Lansley succeeds in ending mixed-sex accommodation he will achieve a goal which eluded Labour ministers for over a decade.
Tony Blair first called for the abolition of mixed wards in 1996, when Labour was still in opposition, saying it should not be beyond "the collective wit" of ministers to achieve.
However, two years ago, Lord Darzi, an eminent surgeon who was made a health minister by Gordon Brown, concluded the aim of providing single-sex wards across the NHS was an "aspiration that cannot be met".