Plans to make all health professionals take out insurance could spell the end of independent midwifery in England, the government has been warned.
The government has promised mothers more choice
The Independent Midwives Association (IMA) says its members cannot get professional indemnity insurance.
It warns that without a rethink independent midwifery will effectively become illegal.
The Department of Health said efforts were being made to find a solution, but safety could not be compromised.
Midwives employed by the NHS are insured via the NHS Litigation Authority, but this is not an option for their independent counterparts.
The IMA warns that childbirth is a high-risk area for insurers, as negative outcomes are expected, blame is often hard to prove and insurance payouts can run into millions of pounds.
As a result, it is effectively impossible for independent midwives to secure insurance.
The IMA is calling for its members to be exempted from the new rules, or for measures to ensure they have access to affordable insurance.
Without action, it warns that a service which plays a key role in helping to relieve the pressure on the NHS will be forced out of existence.
The IMA says this will put even more pressure on NHS services, which are already struggling to cope with staff shortages and increased demand.
It would also fly in the face of the government's aim of giving women more choice about where and how they give birth.
Virginia Howes, of Kent Midwifery Practice, said: "It appears that those who are framing the legislation do not realise what is at stake.
"Independent midwifery could be killed off completely; taking away a service which fulfils many of the government's declared objectives for maternity care.
"The one-to-one care provided by independent midwives has been shown to result in more normal births, reduced Caesarean section rates, improved mother-baby bonding and more breastfeeding, all of which has a major beneficial impact on the health of women and babies across the country."
A Department of Health spokesperson said efforts were being made to find alternative arrangements for independent midwives.
"We are hopeful we will make changes that will enable independent contractors, if they are commissioned by a Primary Care Trust, to access the NHS Clinical Negligence Scheme.
"While it is important to support the employment of independent midwives, especially in relation to extended choice and diversity of provision, it cannot be at the cost of safety to the woman and her unborn child."