A campaign group has criticised the government after discovering an NHS trust charged 739 women for maternity care.

Newham Save our NHS activists revealed that Newham University Hospital in Plaistow, The Royal London Hospital in Whitechapel and Whipps Cross University Hospital respectively invoiced 456, 163 and 120 maternity patients.

The 2018-19 figures emerged after campaigners - who fear migrants are put off seeking NHS treatment as a result of charges - asked board chiefs at hospitals operator, Barts Health NHS Trust, for the totals at a meeting in January.

Newham Save our NHS chairman, Alan Cooper, said: "Charging may frighten residents from going to hospital, including women who could never afford to pay thousands of pounds to have a baby."

The group linked the charges to the "hostile environment" - government measures designed to make staying in the UK difficult for people without leave to remain - saying Barts was following "complex" rules which can lead to "mistakes".

NHS treatment is only free to people who are ordinarily resident in the UK or legally exempt from charges. When the NHS does not have accurate information about a patient's immigration status, it seeks this from the Home Office.

Rosamund Mykura, from Newham Save our NHS, warned: "Sending patients' names to the Home Office for checking is bad for public health and for affected patients."

The trust has a legal duty to find out if charges apply to patients and to recover money from anyone not entitled to free treatment.

A Barts Health NHS Trust spokesman said: "Like all NHS trusts, Barts Health follows the national policy issued by department of health and social care and does not have discretion to waive charges that apply for patients who are not eligible for free NHS care.

"Anyone needing immediately necessary or urgent treatment will always be treated and not turned away, including maternity patients, as all maternity care is considered immediately necessary.

"Our overseas visitors team work with our patients, including the most vulnerable in society, to establish whether exemptions may apply."

On February 23, campaigners wrote to the secretary of state for health, Matt Hancock, complaining that charging mothers for maternity care discriminates against women. They urged him to end the charges.

"Fear of destitution and other consequences of being unable to pay, such as not accessing maternity care at all, must be extremely stressful and negatively impact on pregnancy outcomes for these women", their letter states.

A department of health and social care spokeswoman said: "The NHS is funded by taxpayers and it is only right that those who do not live here on a lawful, settled basis contribute to the cost of their care.

"However, we are clear the urgent treatment, including all maternity services, should never be withheld and we are supporting trusts to ensure these rules are fully understood."