The housing minister yesterday reiterated that the government would not dilute measures intended to cool the property market, despite growing protests from estate agents. "The cooling measures are necessary because they are intended to dampen demand, particularly the sentiment that the market will go up and not go down," Secretary for Transport and Housing Professor Anthony Cheung Bing-leung said. "We don't want a repeat of an asset bubble bursting." His comments follow efforts by an alliance of property agencies to get lawmakers' support to scrap one increase in stamp duty on property transactions and moderate another. The alliance wants February's doubling of stamp duty on all property purchases except those by Hong Kong permanent residents who are first-time buyers scrapped. It also wants an exemption from an additional stamp duty of 15 per cent - payable by corporate and non-permanent residents - for purchases by companies majority-owned by permanent residents. The alliance was formed last month by the chiefs of Centaline Property Agency and Midland Realty, and Hong Kong Real Estate Agencies General Association chairwoman Chu Kin-lan. But Cheung said any exemptions could create loopholes and threaten the effectiveness of the cooling measures. A Legislative Council bills committee will resume discussion of the stamp duty increases on September 23, and the Housing Bureau has met three political parties to explain the rationale behind the cooling measures. Cheung claimed the city's housing problems had widened social divisions and exacerbated class tensions.