A quarter of Mayday’s nursing posts are vacant and health bosses believe the shortage is due, in part, to the high cost of living in London.

There are currently 240 trained nurse vacancies in Croydon.

Mayday Healthcare Trust believes nurses working nearer to the centre of London are attracted by an inner London allowance, having an adverse effect on outer London areas.

And it also blamed a national shortage of specialist nurses in areas such as midwifery, children and A&E.

However, the number of vacancies is reflected in other hospitals in similar outer-London areas. The trust says it has made up gaps by hiring temporary agency nurses, which has put a strain on the hospital’s finances, and has also recruited midwives from Scotland, where there is a surplus.

A spokesman said: “Turnover of nursing staff at Mayday is only slightly higher than the south-west London average and we believe that this may have something to do with the more transitory nature of our population.”