Opposition Leader Tony Abbott meets with children during his visit to the Majura Park Childcare centre together with his wife Margie.

Opposition Leader Tony Abbott meets with children during his visit to the Majura Park Childcare centre together with his wife Margie. Photo: Alex Ellinghausen

The federal Coalition is being challenged to commit more funding to childcare after promising parents a review to make childcare services more flexible and affordable.

Childcare and workers groups say there can be no reform without substantial increases in benefits, but Opposition Leader Tony Abbott says while the system needs to change it must be within ''existing funding parameters''.

Labor Childcare Minister Kate Ellis has warned a lack of information about the likely outcome of the proposed review means families could face a ''terrifying'' wait to see if rebates are slashed or means-tested.

Mr Abbott on Monday visited Majura Park childcare centre in Canberra to announce the proposed terms of reference for a Productivity Commission review of childcare under a Coalition government.

The review would examine ways to give families greater choice, thereby increasing women's participation in the workforce and delivering economic benefits.

Under the terms of reference, the commission would consider the hours parents work and study, needs of regional parents and shift workers, out-of-pocket costs, availability of rebates and subsidies, needs of vulnerable children and types of childcare, including the use of nannies and au pairs.

''Families come in all different shapes and sizes these days. Workplaces come in all different shapes and sizes, which means childcare must come in all different shapes and sizes,'' Mr Abbott said.

''Our childcare system was generally formulated a generation ago, when the vast majority of people were working nine to five.'' Official figures show more than 110,000 parents say they cannot pursue employment opportunities because of a lack of suitable or affordable options offered by the nation's 14,400 care services.

But Ms Ellis said Mr Abbott had admitted that not only did the Coalition not have a childcare policy, it did not intend to adopt one.

''They expect the Australian public will blindly follow them into an election,'' she said.

Parents did not know whether the childcare benefit would be cut or means tested and had been given ''zero answers'' about a Coalition approach to the issue, Ms Ellis said.

Greens Senator Sarah Hanson-Young supports a childcare review but said it was a mistake not to consider extra money for the sector.

''It's not good enough to have a review and not commit to funding the outcomes,'' Senator Hanson-Young said in Canberra.

The Australian Childcare Alliance said that ''Families certainly cannot wait a couple of years to have the affordability issue addressed,'' the alliance president Gwynn Bridge said.

United Voice, which represents childcare workers, fears any changes could lead to rebate and benefit cuts.

''There is no new money in this from Mr Abbott,'' union spokeswoman Sue Lines said.

''By including nannies or au pairs we are going to make an amount of money stretch even further and the only way that can happen is by making deep cuts to families already using childcare through their rebate or their benefit,'' she said.

The Australian Chamber of Commerce and Industry said a review was a worthy cause if it encouraged more people into the workforce. AAP