Indonesia's "King of Dangdut" Rhoma Irama opened his presidential campaign headquarters on Saturday in a move that left at least one rival candidate questioning how a dangdut singer was qualified to lead the fourth-largest nation on earth.

The celebrity, who has made no secret of his presidential aspirations, secured the support of the National Awakening Party (PKB), a small but popular Islamic party associated with Abdurrahman Wahid – the former Indonesian president popularly known as Gus Dur.

The party has thrown its support behind several presidential candidates in the lead-up to the election, including former Constitutional Court chief Mahfud MD and former vice president Jusuf Kalla, but has yet to announced a two-person ticket for the race.

Rhoma, clad in a PKB-green batik shirt, took the microphone on Saturday, shed a single tear and then launched into a rousing rendition of his hit song "Hak Asasi," ("Rights") leading the crowd of fans gathered outside the "Rhoma Irama for Republic of Indonesia," headquarters on Jalan Dewi Sartika, in Cawang, East Jakarta, in an ode to individual freedom, according to reports in the Indonesian news portal Liputan6.

"Religious... Freedom..." Rhoma sung to the crowd. "That's our right," the crowd sung back. "As long as it does not violate the Pancasila," the singer clarified.

Indonesia's constitution protects the rights of six religions – Islam, Protestantism, Catholicism, Hinduism, Buddhism and Confucianism – but not several others, like animism, that are practiced throughout the archipelago.

Rhoma, a Sunni Muslim, has attracted controversy in the past for his less-than-tolerant speeches urging Jakarta residents to vote along race and religious lines. The sermons, delivered at area mosques, were seen as a failed attempt to bolster support for former Governor Fauzi Bowo, who was staging an unsuccessful re-election campaign against current Governor Joko Widodo and his running mate Basuki Tjahaja Purnama – a Chinese Christian.

The statements, while controversial in the press, have seemingly done little to hurt his base. Rhoma's campaign office, dubbed Riffori for short, will be run by volunteers who say they are committed to the rock singer's presidential bid.

"We appreciate the PKB for trusting Rhoma Irama," Riforri chairman Waskito told local media. "Riforri is supported by volunteers who sincerely want to support a person who deserves to be supported."

But rival candidates were less than convinced that Rhoma deserved the people's support. Former Army General Wiranto, who is staging his own campaign, scoffed at the thought of Rhoma Irama sitting in the Presidential Palace.

"These days a dangdut singer in a [presidential] candidate," Wiranto told the Indonesian news portal Detik.com. "Before long, acrobats will be nominated as well. This is why corruption keeps going on and on."

Rhoma brushed off the criticism on Saturday, offering some advice to the former general. "Listen to the words of God," he told Detik.com. "You, Wiranto, should not insult people. Who could know if another person is better than yourself?"

PKB chairman Muhaimin Iskandar suggested that Wiranto take a look at himself before slinging mud at others. "Who has more knowledge? Rhoma Irama or Wiranto?" Muhaimin told Detik.com. "I'm sure Rhoma has more."

Wiranto's words received the backing of the People's Conscience Party (Hanura), which is supporting the former general's campaign. Hanura lawmaker Yudy Chrisnandi defended Wiranto's statement, explaining that a presidential candidate shouldn't be going around to stumping events and singing like a celebrity. It wasn't meant as a dig at Rhoma's chosen profession, the lawmaker said.

"[Wiranto] did not mean to attack Rhoma Irama," Yudy told Detik.com. "Pak Wiranto was only speaking in general terms. If you are named as a presidential candidate, then you shouldn't be performing [as a musician at the same time]."

The former general, himself a controversial figure, last polled below Rhoma on voter popularity. A survey conducted by the Indonesian Institute of Sciences (LIPI) named the "King of Dangdut," as the nation's third-most popular candidate, behind ex-president Megawati Soekarnoputri and former vice president Jusuf Kalla, polling at 89.2 percent.

Wiranto trailed in sixth place, polling at 77.8 percent last May, according to the Indonesian newspaper Kompas.

Joko Widodo has since edged-out the competition in a series of more recent polls, many of which failed to include Rhoma's name. The presidential election is scheduled for July. Only candidates who received the support of 25 percent of the seats in the House of Representatives or backed by a coalition that secured 20 percent of the total vote in April's legislative election can run.