A row over whether a new hospital plans to leave enough space between beds to prevent the spread of infections such as MRSA has gone to the High Court.
Beds should be several metres apart
Former architect Alan Spence argues plans for the new University College Hospital in London flout NHS Estates' guidance on minimum space between beds.
His solicitor lodged a judicial review application on Monday.
The new hospital, to be built under the private finance initiative (PFI), will replace the UCH and the Middlesex.
NHS Estates, which oversees design and planning matters, stipulates that there should be 3.6m (11ft 8ins) between hospital beds.
But the new 18-storey UCH, due to open next year at a cost of almost £422m, has just 2.7 metres (8ft 8in) between beds.
Mr Spence spotted the problem when shown around the hospital with other local residents earlier this year.
He instructed Christian Khan solicitors to take up the case after the NHS trust refused to back down and move the beds further apart.
In a statement UCH said the design of the new building was signed off in 2000, two years before the new NHS Estates' guidance on bed spacing.
A spokesman said: "At that time the plans met the required bed spacing guidance.
"If the trust was to now adapt the design of the new hospital to meet subsequent guidance it would lose approximately 200 beds."
Hospital-acquired infections are estimated to kill at least 5,000 patients a year, although some believe the true figure is much higher.
Mr Spence, a local community activist, said: "It is appalling that a new NHS hospital should be planned in such a way that patients will be put at risk of infection.
"The safety of the patients should be the paramount consideration in the planning of the hospital and not left to chance."
Mr Spence's solicitor James Bell said he had been led to believe other PFI hospitals were blighted by the same problem.
He said: "If Mr Spence is successful in his challenge, hospitals around the country
which are being built under PFI will have to be planned in a way that puts the welfare of the patients first and the desire of the NHS to cram in as many beds as possible second."
The hospital spokesman it had placed "great emphasis" on the control of infections.
"A whole floor has been planned to accommodate patients with infections, mostly in single rooms.
"The new hospital has 150 single rooms, a significant increase on present arrangements.
"Ventilation throughout the hospital is good enough for an isolation unit and it is nearly impossible to approach a bed without passing a hand wash basin."
He added that detailed plans had been approved by NHS Estates, the trust's chief nurse and consultant microbiologists.