The call came on Sunday after the head of the elite unit was relieved of his duties.
It was seen as a clear sign that efforts to remove President Gloria Macapagal Arroyo remained alive two days after she imposed a state of emergency, saying the takeover plan had been quashed but that "treasonous" elements remained.
Several left-wing protest leaders rushed to marine headquarters in suburban Manila to show their support for the restive forces, even though the state of emergency bans public rallies.
Dozens of opposition supporters including Teofisto Guingona, the former vice-president, who resigned after breaking with Arroyo two years ago, gathered at the camp and sang the national anthem.
Three armoured personnel carriers, a tank and about 300 marines also arrived and went inside before the gates were closed. It was unclear where their loyalties lay.
Several dozen riot police took up positions outside the camp and sealed off a road leading to it.
"The most important thing is for the soldiers not to fire at each other," said Senator Ramon Magsaysay, an Arroyo critic, who was at the camp.
The marines were widely rumoured to have been among military units involved in the coup plot.
The military said on Friday it nipped the plan in the bud before it could be launched.
Arroyo has imposed a state of
Major-General Renato Miranda was relieved as commandant of the marines.
Lieutenant Colonel Tristan Kison said Miranda had asked to be relieved of duties, citing personal reasons.
Other reports suggested he had been forced out.
Marine Colonel Ariel Querubin, named by the military on Friday as a main figure in plans by marine officers and their troops to withdraw support for Arroyo, said he was joining Miranda in a show of support.
"Then we'll ... wait for all the people to really come here and protect us," he said.
Asked what they needed protection from, Querubin said, "From aggression."
Brigadier General Nelson Aliaga, who took over as marines commander, claimed the situation had no relation to politics, calling it an internal matter.
Kison said Miranda had not been implicated in the coup plot.
Marines had apparently planned
to walk out last Friday
He also played down widespread rumours of unauthorised troop movements and disgruntled troops.
"Let us remain calm, there is no reason to panic," Kison said.
A statement from the presidential palace said Miranda asked to be relieved and Querubin was to be taken into custody.
It denied any unauthorised troop movements and blamed the reports on JV Ejercito, son of former President Joseph Estrada.
Ejercito responded: "I don't know what they're talking out."
Querubin confirmed that the marines had planned to walk out on Friday in a show of support for the anti-Arroyo camp, saying a majority of the elite force was ready to go but found the camp sealed in a security clampdown.
"The junior officers are really raring, they're so agitated, so I told them to avoid clashes and shooting, let us just march," he said.
The Marines camp was
surrounded by military vehicles
Inside the marines camp, a mass of media personnel swarmed around anyone willing to talk.
After Querubin went into a building, a marine colonel, accompanied by a dozen armed men, approached TV crews.
A higher officer ordered him: "Get inside, don't talk to them (the media) they're not the chain of command."
"I'm just showing my disappointment, sir," the colonel replied.
The 8000-strong marines are regarded as an elite, well-armed unit at the frontline of the government's war against Muslim and communist guerrillas and al-Qaida-linked fighters in the country's volatile south.