Lives of mothers-to-be and their babies are at risk due to budget cuts and midwife shortage, says a report by the Royal College of Midwives.
With the raising birth rate and complex births, midwives are struggling to cope, said the union.
The RCM has warned that the squeezing of services could have a major impact and mistakes "will almost certainly be made", with patients put at risk. A poll of 83 heads of midwifery at NHS trusts found a rise in the number of units that had closed their doors to mothers in need.
Nearly 42 percent of units closed in the last year because they could not cope. Around 90 percent of the senior midwives said that their unit was dealing with more complex cases than the previous year.
The RCM report said that services such as home births and postnatal care are also suffering as staff working in the community are called in to cover gaps in hospitals.
Cathy Warwick, chief executive of the RCM, said, "All of this shows a system that is creaking at the seams and only able to deliver high quality care through the efforts and dedication of its staff. When services are operating at or beyond their capacity, safety is compromised and mistakes can, and almost certainly will be made, through no fault of the dedicated staff delivering the service."
"The Government is responsible for this and it is they who are letting down women, babies and their families, as well as the staff they purport to value. This is simply not acceptable," said Warwick.
A Department of Health spokeswoman said, "We're determined to make sure every mother and baby gets the highest quality care no matter where they live. We've invested in 1,900 more midwives and 3,600 more health visitors since 2010 and NHS England has commissioned a major independent review of maternity services for women and babies across the country."