Midwives presented new evidence yesterday of a spiralling funding crisis in England’s hospitals that has opened up a £340 million cash gap in maternity services alone.

The dangerous shortfall is the result of the current payment-by-results (PBR) system that pays fixed fees for care that is “bought” by NHS commissioning bodies.

A Royal College of Midwives (RCM) study estimated that the gap between hospitals’ maternity costs and the amount they were paid under the national tariff leapt by £40m between 2011-12 and 2012-13 according to the most recent figures.

The RCM warned that huge pressure on resources had caused staff-to-patient ratios to plummet, leaving new mothers without basic care during labour and after giving birth.

It said that 3,200 more midwives were needed now to deal with growing birth rates.

And it predicts that a looming “retirement bulge” will leave the NHS desperately short of skilled staff in future, forcing even more fed-up staff out of the job.

RCM chief executive Cathy Warwick demanded yesterday that the government mount an urgent review.

“The cost of keeping services running is being pushed onto trusts, midwives and other NHS staff,” she said.

“Services are stretched and midwives don’t have the time to support women in the crucial period after a baby is born.

“These moments are some of the most precious in a woman’s life, and are vital in ensuring the continuing and long-term health of the mother and baby.”

Healthcare campaign Health Emergency leader Dr John Lister warned that the PBR system was pushing ­hospital trusts to the brink of collapse in other areas too.

“Staff are working under impossible conditions,” he said.

In A&Es faced with more patients as a result of recent closures, hospital trusts are only paid 30 per cent of the full tariff for each person they treat above 2009 estimates.

“They lose money on every one,” he said.

PBR was introduced by Tony Blair’s Labour government as part of market reforms that introduced a divide between commissioners and trusts — mainly hospitals — that provide services.