As many as 30,000 property agents and others working in the industry, such as decorators, could join a protest march on Sunday against stamp duties that organisers say have bled the sector dry.
About 20 per cent of companies faced closure and nearly 20,000 people were expected to lose their jobs in three to six months if the government did not lift the taxes soon, warned Shih Wing-ching, director of the Centaline Group, one of the city's biggest real estate agencies.
"The [stamp duty] measures are not practical in that they are not solving the problem" of rising prices or making property more affordable, Shih said.
He called the planned protest a rare occasion of unity and solidarity, with more than 30 real estate and related professional guilds and co-operatives coming together to form a coalition.
Supporters will march from Victoria Park to the government headquarters in Admiralty.
The coalition is calling for an end to the doubling of the stamp dutyas well as an exemption for companies owned by permanent residents from corporate buyers' stamp duty of 15 per cent, in place since October. It also wants the six-month exemption on special stamp duty extended to 12 months. Special stamp duty is payable when a property bought after November 20, 2010 is sold within a two or three years.
Three rounds of measures have been introduced since late 2010 to deter speculators.
Shih said business in the sector had plunged 70 per cent since the first tough tax - the special stamp duty - was launched. Commercial and industrial properties were hit, on top of housing.
"The government has the right concept, but the method is completely wrong," said Pierre Wong Tsz-wa, managing director and executive director of Midland Holdings. "The stamp duties benefit no one." He said the three rounds of tough measures were like "feeding everyone poison just to kill the few who are causing problems".
The number of transactions last month fell 12.7 per cent to 4,616 compared with May, Land Registry data showed. Sales volume declined 45 per cent compared with June last year.
At Midland Realty, a subsidiary of Midland Holdings, transactions plunged in the past three months, chief analyst Buggle Lau Ka-fai said. The company recorded 8,302 and 9,643 deals in January and February, respectively, but only 6,841 in March. In the next three months, deals had hovered between 4,000 and 5,000 per month, Lau said.
The fall in sales has seriously hit the performance of Midland Holdings. The company said it was likely to record a loss for the six months ended June 30.