Thailand's prime minister, Thaksin Shinawatra, under pressure from a vocal opposition movement, says his government will hold a national referendum on whether to amend the constitution. The prime minister made the remark as thousands of demonstrators, watched by several thousand  police, gathered in Bangkok calling for the Thaksin government to resign.

Thaksin Shinawatra

In his regular Saturday address, Prime Minister Thaksin Shinawatra announced that the referendum would be held in April, saying he would seek the opinion of the majority of the people.

Earlier, he explained the purpose of the referendum.

"[To] solicit some ideas of the people nationwide, what do they think, what do they want to change, because the constitution belongs to the people, not to any interest group," he said. " So we would like to solicit the ideas of the whole nation. And we go by majority rules."

The prime minister was speaking ahead of a second consecutive Saturday evening rally calling for his government's resignation. Thousands of demonstrators gathered near the royal palace in

Sondhi Limthongkul leading the rally in Bangkok

, watched by police in riot gear.

Organizer Sondhi Limthongkul led the crowd in chanting for Mr. Thaksin to "get out." There were fewer people than last Saturday, when tens of thousands held an all-night vigil in the same place. Organizers said the crowd was smaller because police, up until the last minute, said they would not allow the rally.

Sondhi told VOA his rallies have succeeded in informing at least the Thai middle class of abuses of office by the government.

"The knowledge that I have dispersed among the people are (is) getting momentum and I think that is a success," he said.

Anti-Thaksin rally in Bangkok

He said he is handing overall leadership of the movement to an alliance of more than a dozen civic groups.

Sondhi began staging anti-government rallies after his talk show on state-owned television was cancelled. The show aired numerous allegations of corruption and abuse of office by the Thaksin government.

Public discontent swelled after the Thaksin family (three weeks ago) sold nearly $2 billion worth of stock, without paying any taxes, in the company founded by the prime minister. The tax-free sale was ruled legal, but many Thais objected to one of the country's wealthiest families avoiding taxes.

Since then thousands of people, including professors and students at Thailand's major universities, have signed petitions calling for the government to resign.

However, Mr. Thaksin has rejected the calls and during the week received visits from thousands of supporters urging him to stay on.

Mr. Thaksin was re-elected one year ago in a landslide victory, and continues to receive strong support from the rural poor, who have embraced his populist policies.

He is the first Thai prime minister in modern history to complete his first term.

Some civic groups want Thailand's nine-year-old constitution to be amended in order to prevent any single individual from accumulating too much power.

After decades of military dominance over politics, Thailand enacted a constitution in 1997 that was meant to strengthen democratic institutions. The charter also contained measures to address the history of weak and fractious civilian governments that repeatedly fell to votes of no-confidence, or to military coups.