Patriot has called for military intervention should riots break out at the Dec 8 rally to "celebrate" the non-ratification of the International Convention on the Elimination of All Forms of Racial Discrimination (Icerd).
Mohamed Arshad Raji, the president of the veterans' group, also urged organisers to rethink holding the rally – initially slated to object the ratification of Icerd, but later changed to a "celebration" when Putrajaya walked back the proposal.
Arshad expressed concern that the rally could be used as a catalyst for riots, as he claimed many heated speeches and statements have been made of late, some even dredging up the spectre of the May 13,1969 incident.
"Most that lived through that dark period would not want to be a witness to such catastrophic and horrendous scenes of destruction and burned bodies strewn across the streets of Kuala Lumpur ever again.
"We, members of Patriot that had served the armed forces and the police during those trying periods in our nation’s history, were witness to such horrendous scenes...
"It is for this very reason we urge the organisers of the Dec 8 anti-Icerd rally, that is primarily a Malay-based rally, not to proceed with the event," he said in a statement.
Arshad also urged the chief of defence forces to pledge military support to the police should events escalate on the day.
"In view of the insistence of the organisers of the rally to proceed, and coupled with the fear by the general public of a possible riotous situation resulting from the rally, Patriot urges the chief of defence forces to come forward with a committed announcement that the armed forces will come forward in force to support the police should anything untoward occurs during the rally.
"Such an announcement will give confidence to the general public that their safety and security is assured."
Zulkifli Zainal Abidin currently serves as the chief of defence forces.
In September, Prime Minister Dr Mahathir Mohamad told the UN general assembly that Malaysia would ratify all remaining human rights conventions.
This caused many quarters, especially opposition parties and Islamist groups, to protest, citing fears that the ratification of Icerd would jeopardise Article 153 of the Federal Constitution, despite assurances from Putrajaya that it would not.
This led PAS and Umno to announce a joint protest against the UN treaty on Dec 8 at Kuala Lumpur.
Ummah, a coalition of Malay-Muslim NGOs, claimed to have applied for approval to hold the rally, but pledged to gather at least 500,000 people at Dataran Merdeka even without a green light from authorities.
However, the Pakatan Harapan government yesterday announced that it had decided against ratifying Icerd.
Organisers vowed to go ahead with the gathering regardless, albeit now labelling it a celebration instead of a protest.