Tens of thousands of people have protested in the Thai capital, Bangkok, in the latest of many rallies demanding the prime minister's resignation.
Some of the demonstrators protested late into the night
The peaceful rally was part of a campaign to remove Thaksin Shinawatra before next weekend's snap election.
Organisers repeated calls to King Bhumibol Adulyadej to appoint a new government before the general election.
Mr Thaksin's critics have accused him of corruption and abusing power, which he denies.
The king's advisers have publicly called for calm and dialogue, but the palace has otherwise kept its distance.
Another anti-government march is planned for Sunday.
Protest leader Sondhi Limthongkul told protesters the crisis had "reached an impasse".
The large crowds in central Bangkok chanted "Thaksin Okbai" or "Thaksin get out".
"We are here to fire Thaksin from office," Wanwipha Maenmanede, a 45-year-old state power company employee told the Associated Press news agency.
"He is the most corrupt prime minister in the country's recent history."
Thousands of Buddhist monks held a simultaneous rally to pray for urge peace and reconciliation.
Mr Thaksin has given no sign that he is ready to give ground or resign before the poll on 2 April.
On Friday, he warned that Thailand faces a nightmare if protesters refuse to respect the outcome of the poll.
Mr Thaksin called the election in the hopes of getting a fresh mandate
He called the snap election in an attempt to refresh his mandate after he was accused of abuse of power.
Pressure has been building on Mr Thaksin since the sale in January of his family's controlling share of a huge telecommunications company for a tax-free $1.9bn.
Our correspondent says Mr Thaksin's efforts to clear the air with an election were spoiled by the three main opposition parties, who have decided to boycott the poll.
Rather than resolving anything, the election may plunge the country into a cycle of political uncertainty, our correspondent adds.