The Labor MP last month called for special consideration for bushfire victims around the December 31 deadline for the program, which provides $25,000 to stimulate new home construction or renovations.

But in a letter to Labor leader Anthony Albanese received on July 1, the prime minister confirmed the deadline would not be extended.

"This is yet another blow for people already struggling following a catastrophic event," said Ms Templeman. "At the six-month mark, some people are still just trying to get back on their feet, let alone get all the things in place to sign a contract."

Federal housing minister Michael Sukkar responded angrily to the claim, saying the scheme still had flexibility which could help bushfire-affected families.

"If construction cannot commence within three months of signing a building contract, states and territories have the discretion to extend this period if the delay is due to unforeseen factors (eg. delays in building approvals). This could help accommodate some of the challenges faced in rebuilding throughout bushfire affected regions," he said.

He accused Labor of not supporting the HomeBuilder scheme.

"If Susan Templeman and Labor had its way, there would be no HomeBuilder. Does Ms Templeman now claim to support the program, contrary to her leader and Labor's housing spokesman?"

But the Macquarie MP said the minister was "attempting to muddy the waters on this issue".

"Six weeks after Labor began calling for a national housing stimulus plan, HomeBuilder was announced and it was a massive missed opportunity. Industry representatives from the Master Builders Association and the Property Council of Australia, to the Community Housing Industry Association, National Shelter and Homelessness Australia, called for much more substantial packages."

Ms Templeman said she had spoken to many Hawkesbury and Blue Mountains bushfire survivors about the issue.

"For families like the Keziks in Bilpin, they've only just found out likely BAL ratings on their land and now they have to choose a location and design for a new home, get all the relevant council and RFS approvals, plus work out how to cover the difference between the insurance and the actual coat of the rebuild.

"And people are making these huge life decisions while still coming to terms with the loss of everything they owned."

Chris Kezik doubted the family would be able to meet the deadline in time.

"I very much doubt we will meet the deadline, with all the assumed delays through council. We are only just starting the process with builders," he said.

Ms Templeman said a total of 41 houses were destroyed in the Blue Mountains and Hawkesbury in the bushfires, with another 23 severely damaged.

"So that leaves 41 households potentially missing out on a much-needed $25,000 through HomeBuilder that would help them rebuild."