Sondhi Limthongkul, a PAD leader, told a press conference yesterday that members of the alliance had faced intimidation while campaigning in northern provinces.

He said they had learned that the government had hired local villagers and forestry officials to harass the PAD in Sukhothai, Kamphaeng Phet and Tak.

"We heard that these people are violence prone, so we have tightened security and are remaining peaceful,'' he said.

Sondhi said he had filed a complaint against caretaker Natural Resources and Environment Minister Yongyuth Tiyapairat for hiring people to heckle his weekly "Muang Thai Rai Sapda" talk show earlier this year.

Somsak Kosaisuk, another PAD leader, called on caretaker Deputy Prime Minister Somkid Jatusripitak, caretaker PM's Office Minister Suranand Vejjajiva and caretaker Health Minister Pinij Charusombat to review their positions after Thaksin insulted them by saying that they were merely his helpers.