The NHS is begging recently retired nurses to return to work this winter and offering trusts funding to persuade 'key staff ' to stay on until next spring.

Guidance from the NHS Executive says letters have been sent to 'qualified and unqualified nurses' aged 50-65 who appear to have retired over the past five years 'setting out their options for coming back to work in the NHS, particularly over the winter months'.

A circular issued by NHS director of human resources Hugh Taylor says more than 150,000 NHS staff are now aged over 50, of whom 50,000 are qualified nurses.

It says that offering staff more flexible routes to retirement can help 'extend their contribution and reduce pressure on staffing levels at critical times of the year'.

Trusts often don't consider flexibility because managers believe it may reduce pension entitlement. But the guidance says 'this is rarely the case'.

Roy Tyndall, personnel director at the Royal Liverpool University Hospitals trust, said his trust was already offering staff the initiatives set out in the circular.

He welcomed recognition of the possibilities open to trusts, but warned the publicity might backfire, with a surge of nurses nearing retirement asking for part-time work.