Campaigners trying to oust Prime Minister Thaksin Shinawatra launched a last push on Saturday to topple him before a snap election with a rally aimed at persuading Thailand's revered monarch to intervene.
But the Bangkok rally, which organisers hoped would draw one million people, was attended by only 30,000, police said, about the same number of monks chanting for peace nearby and far fewer than the 100,000 that attended previous demonstrations.
The attendance backed up a poll this week showing that people in Bangkok, the centre of the anti-Thaksin campaign, were getting fed up after weeks of rallies.
The latest was billed as a "united call" on King Bhumibol Adulyadej to replace Thaksin, accused of corruption and abuse of power, before an April 2 election he called three years early in hopes of ending the crisis.
The palace has let it be known that the king is following events closely but it has shown no sign he is willing to act against Thaksin, the focus of anger since his family's $1.9 billion sale of its telecoms empire in January.
Thaksin, the only elected prime minister in Thai history to complete a full term, told Reuters on Friday he did not think the king - who has intervened publicly twice in his 60-year reign, both times against military rulers - would act.