MIDWIVES' ability to work independently - promised by the federal Health Minister, Nicola Roxon - would depend on endorsement by individual doctors under an amendment to proposed legislation that has infuriated women's groups.

Birth advocacy groups will rally today at sites across the country, including the Brisbane headquarters of the Prime Minister, Kevin Rudd, and in Sydney outside the Surry Hills office of the Minister for the Status of Women, Tanya Plibersek, to protest at the amendment, made public last week, which reveals that to work in private practice midwives will first have to ''enter a collaborative arrangement … with one or more medical practitioners''.

Critics say the Government has capitulated to doctors and the move undermines the intent of a series of bills before the Senate, which for the first time would allow midwives' clients to claim a Medicare rebate for their services.

It also threatens rural women's access to birth services, they say, and puts midwives at the mercy of sometimes hostile doctors for their professional registration, Medicare funding and indemnity insurance.

Hannah Dahlen, vice-president of the Australian College of Midwives, said the decision tied midwives' ability to practise ''to the sign-off as a doctor'' - contradicting the World Health Organisation's definition, which describes a midwife as an ''accountable professional [who can] conduct births on the midwife's own responsibility''.

Midwives accepted the need to collaborate, she said, but should be required to have working relationships with health services rather than individual doctors.

''There are particular issues in rural and remote Australia where sometimes there is no doctor, or no permanent doctor, just three-month locums,'' Associate Professor Dahlen said. ''This is not about safety, not about evidence. It's purely about politics. Collaboration's about mutual trust and respect. It's not about one profession choosing when another will or won't work.''

Professor Dahlen said the amendment could prevent new models of pregnancy and birth care envisioned in the law reform - such as midwives working in a group practice - from getting off the ground.

When she announced midwives would be given Medicare rights, Ms Roxon said the $67 million measure would ''improve the flexibility of the health workforce'' and allow patients better access to services.

The amendment is also likely to threaten women's ability to choose to give birth at home, if midwives cannot find a doctor to support them in such births.

Doctors groups - including the Australian Medical Association, which is understood to have campaigned hard for the amendment, and obstetricians' representatives - have been vocal in their opposition to home birth, saying it is unsafe.

Under current rules, midwives can manage home births but are not insured to do so and must disclose this to women. The new law would end this.

Alison Leemen, assistant co-ordinator of Homebirth Access Sydney, said the Government had ducked a potentially furious debate about doctors' veto over midwives.

''It doesn't enable the Senate to have proper scrutiny,'' Ms Leemen said.

''Regulations do not undergo nearly the same level of scrutiny as primary legislation. It's like signing a blank cheque.''