A Liberal MP has announced tens of thousands of dollars worth of grants to community groups in a highly marginal seat before applications for the program have opened, it has emerged in Senate estimates.

Labor senator Kristina Keneally on Thursday told the hearing that the Facebook page of Dunkley Liberal MP Chris Crewther, in posts which have since been deleted, said he and Environment Minister Melissa Price had announced grants of up to $20,000 to three groups under the Communities Environment Program. The posts included videos of the pair with the three groups.

The $22 million program was announced in early March. However officials from the Department of the Environment and Energy told estimates that guidelines for the program have not yet been released and applications will not open until mid-year.

Senator Keneally said the posts state that the MPs had "announced" grants worth $20,000, $10,000 and $7500.