Hundreds of monks swathed in saffron and maroon robes filed early morning into a Yangon monastery for the annual meeting of the Buddha Dhamma Parahita Foundation.
The group was known as Ma Ba Tha until a ban by the government and religious authorities in 2017 aimed at curbing its influence.
Their hostility towards the Rohingya helped whip up public support for a brutal military crackdown nearly two years ago. Some 740,000 fled the country in violence branded as "genocide" by UN investigators.
Despite the ban -- offline and on Facebook -- the group has continued to operate under its new name.
Increasingly taking a radical stance against civilian leader Suu Kyi's government, the group has also sidled-up to the country's still-powerful military.
Monks regularly appear at pro-army nationalist rallies and the military returned the favour at Monday's session.
Yangon Region Commander Major-General Thet Pon openly donated 30 million kyat ($20,000) in cash to the group.
In a written statement, the ultra-nationalist monks said they "harshly condemn" the scrapping of various laws, which they claimed had "allowed -- and continue to allow -- Bengalis to enter the country illegally".
The term "Bengali" is a common slur in Myanmar for the Rohingya, implying they are illegal interlopers from Bangladesh.
The hardliners even urged people in next year's election to vote against Suu Kyi's National League for Democracy (NLD) party, which is widely expected to return to power.
They also sniped at Suu Kyi herself for "stepping foot" in a pagoda reserved for men.
One notable absentee at the meeting was co-leader Wirathu, dubbed the "Buddhist Bin Laden" and also blacklisted by Facebook.
He is currently on the run after a court issued an arrest warrant for alleged sedition following several provocative speeches at nationalist rallies.
The hard-line monks condemned what they called the "unlawful" charges.
(The annual meeting of the ultra-nationalist Buddha Dhamma Parahita Foundation in Yangon on June 17, 2019. Photo: Thura/Mizzima)