A $300 million funding boost aimed at improving the wages of 30,000 childcare workers looks increasingly likely to be axed as the federal government continues to sit on the Labor-approved initiative.

The money was to be spent in 1100 childcare centres to bolster the meagre $19-an-hour wages of certificate III childcare workers by $3 an hour and early-childhood teachers by $6 an hour. The starting wage for a university-educated early childhood teacher is $42,000 a year.

The government wrote to childcare centres who had accepted the funding soon after winning office, revoking the conditional funding offers and advising it was reviewing the $300 million Early Years Quality Fund (EYQF).

Assistant education minister Sussan Ley initially said the review would be completed by the end of October, but it's understood she was only handed the report last week.

Her office said she was considering its findings and would announce the fate of the funding this week.