Data obtained by Labour under the Freedom of Information Act showed that in 2016 there were 382 occasions when units have closed doors, a 70% increase in incidents between 2014 and 2016. Some units have closed more than once.

The figures released today showed across England there were 225 closures in 2014, 375 in 2015, rising to almost 400 last year.

Information from the 96 hospital trusts – out of 136 – that responded to the FOI request indicated nearly half of England’s maternity wards, 42 (44%), were affected by the closures, some of which lasted more than 24 hours.

Ten trusts had to shut temporarily on more than ten separate occasions each.

Jonathan Ashworth, Labour’s shadow secretary of state for health, said: “These findings show the devastating impact which Tory underfunding is having for mothers and children across the country.

“It is staggering that almost half of maternity units in England had to close to new mothers at some point in 2016.”

Sean O’Sullivan, head of health and social policy at The Royal College of Midwives (RCM), said trusts were right to close wards when not doing so risked compromising safety of the service but stressed that persistent and regular closures were a sign of an underlying problem around capacity and staffing levels that needed “immediate attention”.

He added: “The RCM has warned time and time again that persistent understaffing does compromise safety and it’s about time the government listened to those best place to advise.”

According to a report from February, the RCM states the health service has a shortage of 3,500 midwives with over a third soon approaching retirement age.

A spokesman for the Department for Health, said: “Temporary closures in NHS maternity units are well rehearsed safety measures which we expect trusts to use to safely manage peaks in admissions.

“To use these figures as an indication of safe staffing issues, particularly when a number of them could have been for a matter of hours, is misleading because maternity services are unable to plan the exact time and place of birth for all women in their care.”