WA's first homebuyers grant will be cut back to $10,000, after the State Government announced it would end a $5000 boost at the end of next month.

Treasurer Ben Wyatt said the $15,000 grant, announced by the former government late last year and intended to be in place for all of 2017, had not seen a boost in first home buyers.

The move, which is expected to save the State Government $20 million, will come into effect on July 1.

In December, the grant was increased by $5000 up from $10,000 and took effect from January 1,2017.

It was supposed to remain in place for 12 months.

My Wyatt said the previous government’s decision to boost the grant to $15,000 was just an “election cash splash”.

“The boost is not an effective mechanism for stimulating additional construction of homes and given the disastrous state of the finances which we have inherited, we need to remove any ineffective spending.

“Ceasing the boost early will allow the State Government to fund higher priority areas while ensuring Western Australian first home buyers continue to be eligible for generous Government assistance.

“This action represents another $20 million saved over the forward estimates. It’s another step towards budget repair.”

However in December Mr Wyatt, then the Opposition treasury spokesman, said he supported the increased grant and vowed not to remove it if Labor won office.

"I'm glad the government has recognised that they've had a negative impact on that particular industry, but also recognise that the construction industry is a big employer in Western Australia," he said.

"We'll support that (first homebuyers) announcement and don't have any intention of removing that in the event that we win government in March."

Earlier this month, the Real Estate Institute of WA said first homebuyers were the most active in the Perth market.

“First homebuyers remain active and continue to take advantage of improved affordability and choice in the market to secure a property that meets their needs,” REIWA president Hayden Groves said.