BANGKOK:The Thai government said on Monday it was not concerned about a student-led demonstration on Wednesday as protest leaders sought to escalate their push to demand a new constitution and oust Prime Minister Prayuth Chan-ocha.

During three months of protests, anti-government activists have also broken a taboo by calling for reforms of the powerful monarchy of King Maha Vajiralongkorn, who is "enthroned in a position of revered worship" according to the constitution.

Protesters, who drew tens of thousands of people to a demonstration last month, said they planned to gather on Wednesday at Bangkok's Democracy Monument before moving to Government House and would camp there overnight.

Deputy Prime Minister Prawit Wongsuwan told reporters that he did not expect huge turnout.

"We're prepared and not worried," he said. "I think we can handle it."

The protest leaders, organising under the new banner of the People's Movement, said their focus would be a call for constitutional changes before a parliament sitting on Nov. 1.

"We also want to oust Prayuth," said Panusaya Sithijirawattanakul, one of the leaders, adding that she expected even more people than at last month's protest in Bangkok.

Protesters say the constitution was engineered to ensure that Prayuth, who first seized power in a 2014 coup, continued in office after an election last year. He says the election was fair.

Some protesters also want a reduction in the king's powers to reflect Thailand's status as a constitutional monarchy.

Raising the prospect of an encounter between the king and the protesters, his motorcade is due to pass Democracy Monument on Wednesday as he presides over a ceremony at a royal temple during a rare visit to Thailand.

Police said they would urge protesters to choose another location or at least clear the way for the motorcade.

Arnon Nampa, another of the protest leaders, said last week that demonstrators would not obstruct the motorcade but would show a three-finger salute - a symbol of resistance - if it passed by.