Filipino boxing idol Manny "The Pacman" Pacquiao could not help but hit back at the critics of concert king Martin Nievera, who is under fire for singing a different rendition of the national anthem last May 2.

"Naiinggit lang siguro. Gustong pumapel," Pacquiao said, referring to the people who have been criticizing Nievera for his alleged unconstitutional version of "Lupang Hinirang."

Pacquiao told ABS-CBN's morning show, "Umagang Kay Ganda," he doesn't see anything wrong with Nievera's performance at the MGM Grand, where he fought Britain's Ricky Hatton.

"Okay naman ang pagkanta ni Martin ng Lupang Hinirang natin," he said before arriving at the Ninoy Aquino International Airport.

The Concert King drew flak from the National Historical Institute (NHI) and the provincial board of Cebu for his upbeat rendition of the country's national anthem.

The NHI complained that Nievera sang the first part of the national anthem too slow. The institution also scored Nievera for belting out the last part.

Earlier, Nievera said he is ready to apologize for singing the national anthem the wrong way, if needed.

"If I have to do it I will do it. I have to do what is right but I don't want to say sorry for something I'm not sorry for. But, if I have to, I will do it," Nievera told radio dzMM.

The provincial board of Cebu has also passed a resolution condemning Nievera's version of Lupang Hinirang. The board said he violated Republic Act (RA) 8491, or the 1998 Flag and Heraldic Code of the Philippines, by "murdering" the national anthem.

According to Section 37 of RA 8491, the rendition of the national anthem, whether played or sung, shall be in accordance with the musical arrangement and composition of Julian Felipe.

Section 20 of the law also states: "The rendition of the flag ceremony in official or civic gatherings shall be simple and dignified and shall include the playing or singing of the anthem in its original Filipino lyrics and march tempo."

RA 8491 prescribes that any person who will violate its provisions may be punished by a fine of at least P20,000 or imprisonment of not more than one year.