Elections in the expanded ARMM will be held on Nov. 26 unless Congress enacts another law resetting them to a latter date.
"Its high time to cross party lines now so we can pool our political machineries and elect our favored candidate for governor," said Datu Michael Sinsuat, a candidate for the Regional Legislative Assembly (RLA) which, with the expanded autonomous set-up, will now have 27 seats.
President Arroyo earlier announced her choice of Farrouk Hussein of the Moro National Liberation Front as her administrations candidate for regional governor.
The Presidents endorsement of Hussein drew flak from Central Mindanaos Muslim and Christian leaders who have criticized what they described as Malacañangs "perennial" interference in the supposedly autonomous elections.
The first regional governor, Zacaria Candao, ran in 1990 with the blessings of then President Corazon Aquino. In 1993, Candao, a re-electionist, was defeated by Lininding Pangandaman, who was the choice of then President Fidel Ramos.
Mayors of vote-rich Maguindanao towns pledged their support last week for the candidacies of Maguindanaoan Datu Toto Paglas III for governor, and his running mate, Benjamin Loong of Sulu.
"We want the ARMM to be governed by (someone who) we want to become our leader and not one who is being rammed into our throats by Malacañang," one of the mayors said.
Surprisingly, one of those present in the gathering was ARMMs youngest provincial governor, Rashidin Matba of Tawi-Tawi, who is also supporting the Paglas-Loong tandem.
Matba said he will see to it that Paglas and Loong will win in his province during the Nov. 26 ARMM polls.
In Lanao del Sur, religious leaders supporting the candidacy of Husseins running mate, Mahid Mutilan, said they will exhaust all means to ensure the victory of Mrs. Arroyos candidates in the province.
But a Maranaw mayor, who asked not to be identified, said the religious sector supporting Mutilan, a foreign-trained Islamic theologian, must first get the backing of Lanao del Surs 38 mayors.