Parliament President Chai Chidchob first phoned reporters at a press room after 10:00 am (0300 GMT) to announce that the policy debate session, originally scheduled to start at 9:30 am (0230 GMT) and to last two days, will be postponed to 2:00 pm (0700 GMT).

Chai then delayed the session to 5:00 pm (1000 GMT) after the failure of negotiations with protesters, who blocked accesses to the parliament compound from early Monday morning.

By evening, he sent SMSs to MPs and senators, informing them that the debate has been postponed to 9:30 am (0230 GMT) today.

The postponement was decided after thousands of red-shirt demonstrators, who supported former coup-ousted premier Thaksin Shinawatra, besieged the Parliament from early hours of the day in attempts to blockade the new government policy address due to be delivered yesterday morning.

The protesters in red, led by Democratic Alliance Against Dictatorship (DAAD), had gathered from Sunday afternoon at Sanam Luang (Royal Field) square in central Bangkok and moved to rally around the Parliament compound after midnight.

On early yesterday morning, they surrounded the gates to the Parliament and allowed people to get into the compound one by one.

Similar tactics of besieging the Parliament had been used by supporters of the People's Alliance for Democracy (PAD), or referred as the "yellow-shirt" people, to block the previous premier Somchai Wongsawat from delivering the government policy speech on October 7, in an attempt to pressure the Somchai government to step down.

Deputy Prime Minister Suthep Theugsubhan said negotiation was underway between the government and the DAAD protest leaders, including Jatuporn Promphun and Veera Musikapong.

Suthep Thaugsuban reiterated that the government will not use force against the red-shirt protesters.

Suthep was speaking after chairing an urgent meeting with Police chief Pol Gen Patcharawat Wongsuwan and City police chief Pol Lt Gen Suchart Muenkaew.

The protest leaders said the Prime Minister Abhisit Vejjajiva and MPs could walk into the compound.

The DAAD called on the Abhisit government to dissolve the Parliament for a snap general election.

Some 3,000 police were deployed to keep security around the compound. Police earlier released leaflets to the protesters, warning against violent actions by the protesters.

By laws, a government has to deliver policy statement within 15days. For Abhisit government, which took office on December 22, it has to do within January 5, 2009.

The DAAD leaders have threatened to besiege the Parliament through Monday and Tuesday, the scheduled time for the government policy debate.

Abhisit earlier said the government would not resort to force to crack down on the red-shirt protesters.

Somchai government was blamed for ordering police to use tear-gas to disperse PAD protesters on October 7, causing violent clashes that killed two persons and injured more than 400 others.

Democrat Party leader Abhisit was elected new PM after Somchai stepped down with a court verdict on December 2 that disbanded the former ruling People Power Party on electoral fraud charges.