MANILA - The Philippine government, through its secretary of Foreign Affairs, should have filed a diplomatic protest regarding the activities in the South China Sea "a long time ago," a former ambassador said Monday.

The diplomatic protest should have also been written in first person, which would be taken more seriously than one that was written in the third person, said former Ambassador Apolinario Lozada.

"Yung sa South China Sea, I think that we should have done a first-person protest there a long time ago and publicize now in the paper. Let the public know ano talagang sinabi natin," he told ABS-CBN News in an interview.

A diplomatic protest "cannot be expressed verbally unless there is face to face meeting between the two officials," where the Foreign Affairs Secretary would still hand the protest written in the first person, Lozada said.

He explained, in the world of diplomacy "it is the signature of the Secretary of Foreign Affairs that is recognized universally," and the signature of the president is "not important."

“We must really submit a first-person protest; not a third-person. Third person, bale-wala yun. It’s an ordinary note verbale…Pag seryoso ka sa sinasabi mo, it’s always first person,” he said.

Lozada said the public should be informed of what the protest said because they have the right to know. He said that while not everything may be publicized especially if there are quiet talks going on, the people should still be informed of the action taken.

“We should inform the public what is happening because this is a public matter...Kung may mga nag-uusap-usap na quietly, siguro we don’t need to publicize it, but we still have to inform the public because it’s the public’s right to know what’s happening to the territory that is being questioned. Kailagan pa rin,” he said.

The Philippines has taken "diplomatic action" against China over its recent developments in the area that was once-disputed, officials said.

• Philippines taking 'diplomatic actions' vs China over South China Sea activities

Foreign Affairs Secretary Alan Peter Cayetano, during a briefing to members of the House of Representatives last week, said Manila has filed "several dozens" of protests, "maybe 50, 100."

He also said that protests come in many forms, such as filing a note verbale, listing complaints during the bilateral consultation mechanism, and President Rodrigo Duterte telling Chinese President Xi Jinping "That is mine and don't get the oil."