Doctors are backing a plan to strip childcare and welfare benefits from parents who refuse to vaccinate their kids.
The Australian Medical Association supports the federal government's policy, which could cost parents who object to immunisations up to $15,000 in tax-payer funded payments.
The government says the number of parents opting for the "conscientious objection" vaccination exemption for payments has more than doubled over the past decade.
The "no jab, no pay" policy, which has bipartisan support, could affect families of up to 39,000 children under seven who have not been vaccinated.
Children can still be exempted on medical and religious grounds, but the "contentious objection" exemption will be removed on January 1, 2016.
The AMA says its important to encourage vaccinations because it's one of the most effective public health measures available.
But AMA President Brian Owler is concerned the policy won't catch everyone and fears some children could be punished for their parents' decisions.