"I believe Bangkok residents can distinguish between local and national issues," he said.

Democrat candidates are leading in at least 30 districts for the city-council race and are ahead to fill vacant sets for district councillors, he said.

City dwellers will continue to place their trust in the Democrat-led administration, he said.

In fierce local campaigning, the opposition Thai Rak Thai Party has been trying to pin the blame for the Bt6.6-billion fire-fighting equipment fiasco on the Democrats, but constituents will not be swayed, he said.

"Voters understand this and have been able to put the scandal in its proper perspective since I released a white paper on it," he said.

Democrat secretary-general Suthep Thaugsuban said the ruling government party wanted Apirak to take the fall for its suspicious procurement deal.

The government-to-government agreement between Thailand and Austria was negotiated by the Interior Ministry under then minister Bhokin Bhalakula, Suthep said.

A few days before leaving office, then acting Bangkok governor Samak Sundaravej signed the ministry-endorsed agreement and left the mess for Apirak to sort out, he said.

Apirak suspected foul play but was forced by ironclad contract provisions to open a letter of credit to pay for the fire-fighting engines and boats, he said.

The city administration could not cancel the purchase before it uncovered evidence of irregularities, he said.

The Department of Special Investigation (DSI) recently found cause to suspect graft violations, and Apirak promptly refused to take formal delivery of the equipment, he said.

Since the scandal broke, the ruling government party has faulted Apirak for his involvement in the issue of a letter of credit but failed to mention its own role in brokering the deal, he added.

A Democrat Deputy leader Alongkorn Polabutr said he would submit more evidence to the DSI on Thursday asking the agency to conduct more investigation over an involvement of Prime Minister Thaksin Shinawatra and Deputy Prime Minister Surakiart Sathirathai, who is former foreign minister. As the contract was a government to government one so the Prime Minister as the leader and the foreign minister as a representative of the government should know about the deal, he said.