More than one in three families still struggle to pay for child care despite bigger government handouts over the past decade, a new report says.

The Left-leaning Australia Institute think tank says successive Federal governments have done little more than temporarily reduce the cost for families, with the big winner childcare centres' profits.

The report's release today follows the Federal Government announcing yesterday a $300 million pay rise over two years for childcare workers.

As part of reforms that come into force next year, childcare centres can apply for grants to hire more highly qualified staff to boost the quality of care and education.

About 67,000 workers with a certificate III will get an extra $114 a week and higher qualified workers up to $199.

As a condition, centres must commit to restrain fee rises.

But operators have warned the rollout of the national quality framework would force parents to pay more. The United Voice union welcomed the pay rise but said early childhood educators were WA's lowest paid full-time workers.