Kingston Hospital bosses have moved to reassure expectant mothers, after an anonymous letter from midwives raised serious concerns about overstretched maternity staff struggling against understaffing.

In a letter sent to the Surrey Comet, the nurses described "conveyor belt" conditions on the wards, and said some women were forced to wait two days for a labour bed while others went into labour in the antenatal ward.

Kingston Hospital categorically denied claims patient safety was at risk and said its 27 midwifery vacancies were being covered by temporary staff.

The hospital was forced to radically change the way it ran its maternity unit in 1999, when an inquiry into the death of a baby girl identified understaffing as a key issue.

The letter from midwives said: "Whilst some will see this letter as scaremongering, I think it is important these circumstances are made public with a view to obtaining change and assistance.

"We cannot continue working in these conditions indefinitely.

"The hospital has a duty to provide a safe environment for women and to protect the welfare of staff.

"This is not the case at present."

They said numerous complaints about the "shocking" staffing levels have had no effect and some shifts now had as few as three midwives.

It was also claimed midwives were being gagged from telling mothers the truth about bed shortages, instead promoting the virtues of going home as soon as two hours after birth to free up space.

As a result, re-admission rates have increased, they said.

The hospital said it was best practise to send straightforward births home two to six hours after delivery and that re-admission rates were stable at about 5.6 per cent.

The nurses, who signed themselves "concerned midwives of Kingston NHS Trust", said they could not give their names because it would lead to disciplinary action against them.

Carl Chow, consultant obstetrician at the hospital, personally reassured expectant mothers in an open letter published on its website yesterday, which said: "The unit is very popular, which does mean that at certain times it is very busy.

"However, this does not mean that women and babies are put at risk."

He said the hospital was currently recruiting an extra 30 midwives and 40 maternity assistants to increase the number to 190, and plans to increase the hours of a consultant obstetrician on the labour ward from 60 to 96 hours a week.

The hospital is making the changes as part of a Government-led scheme Maternity Matters, to get more midwives out into the community at health centres and GP surgeries.

Kingston and Surbiton MP Edward Davey said: "When my wife and I were in Kingston Hospital maternity unit for over a week in November 2007 we saw a group of dedicated, hard-working staff.

"There's no doubt they were rushed off their feet and I subsequently raised staffing with then chief executive Carole Heatly.

"My understanding was that staff levels have improved since that time and the hospital has plans to further improve them."

Prospective Conservative parliamentary candidate Helen Whately wrote to hospital management after waiting two or three days for a labour bed in August last year, because the hospital was too full.

She said: "From my personal experience it comes as no surprise because I got the impression they were incredibly stretched and the midwives were having to rush between women."

What do you think about the maternity ward? Leave a comment below, email dlindsell@london.newsquest.co.uk or call 0208 330 9547

• Click here to read the letter and the hospital's response

• Click here to read the open letter to local women