The protesters on Monday began searching for members of the Cabinet at their residences to pressure them to resign, but did not find any.
Labour unions representing about 20 state-owned enterprises vowed to go on strike on Thursday to support the anti-government protesters, although several companies, including Thai Airways and the Electricity Generating Authority of Thailand, said Monday that they would operate normally.
Mr. Thaksin, a former telecommunications billionaire, remains highly popular among the poor in the north and northeast, and parties controlled by him have won every national election since 2001. The anti-government protesters, who are aligned with the opposition Democrat Party and backed by the country's traditional elites, say they want to remove all traces of his political machine from politics.
Mr. Thaksin's supporters, known as the Red Shirts, have staged a rally in Bangkok's western outskirts since May 10, raising concerns about possible clashes between them and the anti-government protesters.