Of 37 sales for his office in January, only two had been above $500,000. "If that's not enough evidence for you then I don't know what is," he said. "Every buyer we have now is a first-time buyer and I would say 90 per cent of them are doing it because of the government incentive.

"That extra $7000 may not sound like a lot but it's all about sentiment and I can tell you, the whole property market will crash here. It'll be disastrous." First-time buyers now receive $14,000 for established properties and $21,000 for new properties. However, the grants will revert to $7000 on July 1.

A record 26.5 per cent of new home loans went to first-home buyers in January. The scheme has been credited for reversing a five-year decline in the home building industry and softening the effects of the financial downturn.

The Real Estate Institute of Queensland (REIQ) is working with interstate bodies to lobby the Federal Government to extend the higher grants beyond June 30. REIQ chairman Peter McGrath said the ramifications of the grant were huge, both for the property market and any businesses connected to it. "I cannot stress how important first-home buyers are to the overall health of the property market as well as to their local economies," he said. "The property market is like a ladder. You can cut off the top of the ladder and it still stays up.

"But if you cut off the bottom of the ladder, the whole thing comes crashing down." Mr McGrath said first-time buyers not only kept the real-estate market going but also supported other jobs.

The flow-on included fields such as conveyancing, valuing, lending, building and pest inspection, furniture removal, hardware retail and nurseries. "So not only do first-home buyers allow existing homeowners to upgrade, they also inject funds into their local economies through buying ancillary products and they also use local tradesmen such as plumbers, electricians and builders," he said. "We have to try to make the Government understand how serious this really is and what dire straits the Queensland property market will be in if this grant is not extended."