Story updated to include details of George San Mateo's arrest and posting of bail.

Metro Manila (CNN Philippines, December 5) — PISTON National President George San Mateo posted bail on Tuesday afternoon for his case before a Quezon City court.

Before this, San Mateo had been picked up by several policemen as he was on his way to post bail at the Quezon City Hall of Justice.

Police then brought him to Station 10 of the Quezon City Police District for booking. Afterwards, the police escorted San Mateo back to the Hall of Justice, where he eventually posted bail.

In the December 1 arrest warrant released to the media, Judge Don Ace Alagar of the Quezon City Metropolitan Trial Court Branch 43 found probable cause to order San Mateo's arrest for violating Commonwealth Act No. 146 or the Public Service Law.

Alagar set bail at P4,000.

On October 30, Quezon City Assistant City Prosecutor Marvelous Madamba charged San Mateo in court for violating Section 20(k) of the said law, recommending bail at P4,000.

The charge sheet read San Mateo knowingly and willfully instructed members of PISTON to conduct a nationwide strike.

The case stemmed from the nationwide strike that PISTON and other transport groups conducted in February 2017 to protest the PUV Modernization Program.

Read: Transport groups hold nationwide transport strike to protest government's PUV modernization program

No to Jeepney Phaseout Coalition Spokesperson Misael Melinas told CNN Philippines on Tuesday that the group condemned the arrest order.

"Ang layunin lang po niyan ay pananakot upang pigilan kaming mga driver at operator na ipaglaban ang aming kabuhayan," he said.

[Translation: The only objective of that warrant is to stop us drivers and operators from fighting for our livelihood.]

Melinas added that the group will continue to fight for a "more inclusive" PUV Modernization Program.

Meanwhile, PISTON members and supporters marched to the Quezon City Hall of Justice on December 5 to protest the "trumped-up charges" against San Mateo.

On Tuesday, Presidential Spokesperson Harry Roque denied that the charges were a form of harassment.

"I think he was warned that as a holder of a franchise, a certificate of public convenience...it is criminal and it is illegal for them to participate in any tigil-pasada [halting of service]," Roque said. "He defied. He now has to face the consequences."

He said the purpose of the certificate is to render a service necessary to the public.

"But if you will be a tool to inconvenience the public, then that's a violation of the trust repose in you by the state because that certificate of a public convenience is not a right. It's a privilege reserved only for those who can meet the obligations of franchise holders," he added.

Poe: 'Let's hear them out'

Sen. Grace Poe said on Tuesday that the timing of the warrant's release is "suspect and casts doubt on the intent of the complainant in filing such charges."

"Everyone has the right to peaceably assemble," she said in statement. "It is unclear based on the cited section of the Public Service Act what exactly San Mateo violated. If holding a strike is tantamount to a violation under any memorandum of the LTFRB, then the proper penalty should have been a fine or suspension or cancellation of their franchise, not threatening their leader with incarceration."

Poe added that the Public Service Act should be revisited to better balance public service and the right to assemble.

The senator on Monday that the groups are set to meet transport officials at the Senate on December 11 to discuss their concerns.

Read: Transport group cancels nationwide strike on Dec. 4-5

"With their entire livelihood at stake, the least we can do is hear them out," Poe said. "Moving forward, let us give them and other stakeholders a chance to explain so that we can resolve their issues together."

Melinas said despite the warrant issued against San Mateo, the coalition will still attend the hearing.

The PUV Modernization Program, which was revealed in June 2017, aims to phase out PUVs over 15 years old and replace these with vehicles with "low-carbon and low-emission technology."

Read: Jeepney modernization program kicks off next month

Land Transportation Franchising and Regulatory Board Spokesperson Aileen Lizada told CNN Philippines in June 2017 that there are around 204,000 jeepneys operating nationwide, with an estimated 75 percent of these over 15 years old.

PISTON and other transport groups are against the program, saying that hundreds of thousands of jeepney drivers and operators could lose their business.

Related: Unemployment, debt from jeepney modernization program worry transport groups

CNN Philippines Senior Correspondent Ina Andolong contributed to this report.