Security-related agencies would meet this afternoon to settle on measures to cope with the planned political rallies outside the parliament, which is to recovene on Thursday, National Security Council (NSC) chief Paradorn Pattanatabut said on Tuesday.
Red-shirts calling themselves the People's Radio Media Group began to gather in front of the parliament building on Monday ahead of the re-opening of parliament, in support of legislation to amend the constitution and offer amnesty to offenders involved in the 2010 political violence.
The self-styled People's Army plans to begin an "anti-Thaksin regime" rally on Sunday, Aug 4.
Lt Gen Paradorn said fewer than 10,000 protesters were expected to take part in the Sunday rally.
They were expected to gradually turn up at the protest site, which has not yet been announced.
Although there were no reports of any plan to lay siege to government offices, contingency plans to handle any development had been prepared, he said.
The NSC chief said he would not propose the use of the Internal Security Act (ISA) to cope with the rallies at today's meeting of the cabinet.
Labour Minister Chalerm Yubamrung said he did not want authorities to under estimate the number of likely protesters at the Aug 4 protest, because during the past two weeks the Democrat Party had openly announced it would fully support anti-government rallies outside parliament.
With more than 70% of city and district councillors in Bangkok belonging to the Democrat Party, it would not be difficult for the party to mobilise support for the rally.
Deputy Commerce Minister Nattawut Saikuar, a key member of the United Front for Democracy against Dictatorship (UDD), said the planned anti-government protest on Sunday is constitutional..
There was nothing to worry about since the government was duty-bound to maintain law and order.
Since the Democrat Party had urged people to join in the rally, it should openly declare itself as a leader of the protest so that the public would know the truth, he said.
The Democrat Party had never admitted it had supported anti-government rallies in the past, according to Mr Nattawut.