The National Institute for health and care Excellence (NICE) says that there is more risk of a lower ratio of nurses and nurses to patients.
But it did require that one through eight was an absolute minimum, say that flexibility may be required.
The Department of Health said that the number of front-line staff increased.
Nice, that flexibility, which was necessary, said hospitals should be able to justify a situation, where the recommended ratio of nurses patients was breached.
He said this was because there would be cases where diseases and needs of patients were less severe than normal, and therefore it was set incorrectly, strict limits.
But the manual recommends that nurses to raise the alarm or a "red flag" - if care, no matter what the relationship at risk is.
This could be to manage situations where their vital signs monitor it not enough staff to help patients who use the toilet, or medicines.
Security checkNice Deputy Chief Executive Prof Gillian Leng said: "There is no floor or ceiling number on the required number of nursing staff, which can be applied in the entire NHS."
She added that decisions about the number of nursing staff "flexibility should on basis of daily or layer after layer".
The line, now on consulted before the final recommendations are made in the summer, applies to General acute wards.Their own leaders at a later date receive specialist areas such as maternity, Pediatrics, and accident and emergency.
Nice was asked the question by Ministers, who promised, safe staffing level the following the public inquiry, the Stafford hospital scandal to explore.
Many hospitals have already begun and nurse numbers. for example, a number publicly flaunting actual manpower on stations together with, what they should be.
NHS England wants it through the health service to the routine become, while hospitals have later this year to submit their personal strength monthly, so that they can be displayed on the Web site of the NHS choices.
'Reasonable' instructionsRoyal College of nursing General Secretary Peter Carter said: "for all patients, inadequate care to maintain is unacceptable.
"Nurses are hoping that after completing the full set of guidelines the NHS are ever prone to short-term financial-oriented decisions about patient care."
A spokesman of the foundation trust network, the hospitals represents, said the guidance was "sensible" and supports what already did many trusts.
"Local are best suitable care and clinical teams to assess what is best for the patient," he added.
The Guide also applies to Wales, though it will now be up to Ministers, whether it is applied.
In Scotland, hospitals are already routinely monitor and manpower - publish, there is no recommended minimum.
Health Minister Jeremy Hunt said: "nice work on staff is an important step forward--for the first time in its history, NHS must evidence that it needs to make sure that the nurses able to spend enough time with their patients are."
A Health Department spokesman said Admin staff and managers in hospitals had been cut since 2010, but there were 5,100 more nurses working on stations.
"We have increased the NHS budget in real terms and are obvious, that hospitals must balance its books, and compassionate, to ensure high-quality care for all." We know it can and is happening", he said.