
More than 100 pro-amendment people gathered near the PAD's protest site shortly after the rally began at 3 pm. A crowd leader, Waranchai Chokchana, attacked the PAD through megaphone, using curses and vulgar words from time to time.
Despite the presence of about 30 policemen, some of the pro-amendment people ran after a PAD truck and tore down a banner carrying the message "Don't amend the Constitution if you love the country".
The crowd, many of them from the anti-coup Democratic Alliance against Dictatorship, also burned effigies of the five PAD leaders.
The pro-amendment crowd then hurled plastic bottles at the PAD supporters, who threw them back. The exchange went on for about five minutes before police intervened. A 48-year-old man, identified as Weerayut Seniwongse na Ayutthaya, was slightly injured in the clash.
The pro-amendment people later moved back to their place opposite Satriwithaya School. They continued verbally attacking the PAD and displaying banners condemning its rally.
The PAD rally continued and caused with parts of Rajdamnoen Avenue to be closed to traffic as the size of protesters expanded.
The group claimed that authorities were attempting to block its supporters from the provinces coming to join the rally at the Democracy Monument.
Meanwhile, PAD coordinator Suriyasai Katasila said Sunday that the group would Monday file a petition with the Senate speaker against MPs and senators who filed the amendment motion recently. He said their move was an act against the Constitution and therefore warranted an impeachment campaign.
In a related development, the pro-amendment group Sunday threatened to seek a court order to revoke bail on media mogul and PAD leader Sondhi Limthongkul if he took to the stage at the rally.
Pracha Prasobdee, People Power Party's Samut Prakan MP and leader of the Great Public Group for the Protection of Democracy, said his team gathered at Sanam Luang and Thammasat University to monitor the protest by the PAD. His team was fully equipped with computer and tape recorders to record the incident to be used as evidence. The group would not mobilize supporters to bring confrontation against the PAD as they believe any violent move would give the PAD legitimacy to create violence.
The group would resort to legal measures to be taken against PAD leaders such as Sondhi if he violated bail condition by joining the protest. "We will record Sondhi's speech if he appears and said anything there and we will ask the court to cancel the temporarily release order," he said.
As a second measure, they will seek the public's decision against the PAD be the condemnation or the peaceful protest by asking them to send mail.
If the PAD resorts to road blockade, the group will organise a rally to stop the PAD protest.