More than a quarter of England's popular and successful midwife-led birth centres are being threatened with closure, in spite of government promises to give women more choice over how and where they have their babies.

More than 15 birth centres are under threat as NHS trusts struggle to deal with financial deficits, the Guardian has learned. Just eight days ago, as health secretary Patricia Hewitt spoke to the midwives' annual conference about the need to give more women one-to-one care, the third largest birth centre in the country, in Stroud, was told it must shut because of financial pressure, though there is no question of its success and the admiration in which it is held locally.

Stroud, which has been a maternity unit for more than 50 years, delivered 365 babies last year - 28% of them by water births. It achieves home birth and breastfeeding rates higher than the national average, and a third of the women in labour had their own community midwives with them. A further 350 women who gave birth in hospital - sometimes after Caesareans - then transferred to Stroud to rest and recover.

Richard James, the chief executive of Cotswold and Vale primary care trust, announcing the closure plan, said, "We recognise the high-quality services provided at Stroud Maternity Hospital and acknowledge the strength of feeling and support locally for the facility."

"We're incredibly successful and there's nothing they can say to challenge that," said Mandy Robotham, a midwife at Stroud. "We tick all the boxes. We're accessible and open to all. We have lots of people coming from London, decamping to relatives' houses to give birth here. They come and spend their last weeks of pregnancy in the area."

The government's strategy for better maternity care specifically includes birth centres as well as more home births, and trusts have received extra funding to improve provision.

But Stroud faces the axe because the NHS in Gloucestershire has a total projected deficit of £40m, shared between six health trusts. All maternity services will be centred instead on Gloucestershire Royal Hospital, where there is a midwife-led unit and an obstetric-led unit in the same building.

The midwife-led unit, which delivered 602 babies last year out of a total of 2,830 in the hospital, has itself been closed 17 times in the past three months. The hospital trust says that was because of sickness and that midwives' shifts have now been changed to cope.

Ms Robotham says the Stroud midwives do not believe closing their centre will save money. They estimate the centre's costs at about £400,000 a year. Much of that is staffing costs, and they believe more midwives will be needed in the community because demand for home births is likely to go up. "Faced with the choice of a birth at home or in a large, consultant-led unit, a lot of the women in this area will choose a home birth," she said.

There are around 57 midwife-led units in England, 23 in Scotland and 11 in Wales. Some, like Stroud, are in stand-alone buildings, while others are alongside hospital obstetric units. According to the National Childbirth Trust, mothers like these units, which offer social and psychological as well as physical support. Women who give birth in them are less likely to have medical interventions and ask for less pain-relieving drugs.

But when budgets are squeezed, birth centres can be seen as soft targets, say campaigners. Mary Newburn of the NCT said that they expected more midwife-led units to open after the government published its national service framework on maternity 18 months ago. "But as quickly as they are being set up, some of the established ones are being given notice," she said. Cash-strapped trusts tended to think centralising services was a good idea, she said. "But they overlook the fact that the majority of spending in maternity is in staff time."

Three-quarters of maternity units are already understaffed, according to a Royal College of Midwives survey. Health secretary Patricia Hewitt told the RCM's conference 10 days ago that the NHS was "a long way" from its vision of giving women the one-to-one care in childbirth that they want.

A Department of Health spokesman said £100m had been given to PCTs and hospital trusts in 2001 to improve maternity services - but it was up to them to decide how best to spend it.