Deputy Prime Minister Prawit Wongsuwon will run the Operation Centre monitoring the anti-government rally on Saturday, when protest leaders expect at least 40,000 people to attend.
Prime Minister Prayut Chan-o-cha has set up the centre to keep a close eye on rally-goers, according to a government source.
At least three groups of police officers are being drafted in from today to guard Government House, security cameras have been installed at key locations and mobile electricity generator vehicles will be used in the compound, the source said. More than 8,550 crowd control officers will also be deployed for the event.
Former Future Forward MP candidate Piyarat Chongthep, who is in charge of security on behalf of the protesters, said at least 40,000 people would attend and while 70% of previous rally participants had been youngsters, former red-shirt supporters and those linked to political parties would make up half of the protesters this time.
Sanam Luang would be packed, he said, voicing concerns about security issues as it is an open area, unlike the adjacent Thammasat University's Tha Prachan campus.
"At the outset we asked for volunteers to work as security guards," said Mr Piyarat. "Now we have around 200-300 volunteers and there might be more on the day. All of them must register using their ID card so that they can be verified. This will also prevent third parties from infiltrating in disguise."
Protest leaders who are also students will coordinate with police, he said, adding that they were still trying to persuade university executives to allow them to use the campus during the protest.
If the university agrees, said Mr Piyarat, the Sanam Luang bus terminal would be used as a coordinating centre for volunteers and paramedics.
Organisers also hope to get permission for the protesters to use nearby streets because they need to stay at least until 3am on Sunday, he said, adding that protesters just want to file their demands at Government House and then leave the venue.