The most vocal critic of Philippine President Rodrigo Duterte could be stuck behind the lime-green walls of a Manila prison for a long time.

"Rot in jail" was the destiny the president predicted for his nemesis, Senator Leila de Lima, who has loudly and vigorously objected to his crackdown on suspected drug users and dealers, which has resulted in more than 7,000 deaths.

Suddenly I am the Pablo Escobar of the Philippines? Jesus, where is the proof? They can look and look — they will find nothing. - Philippine Senator Leila de Lima

He has other suggestions, too.

"If I were de Lima, ladies and gentlemen, I will hang myself," Duterte said in August.

That's not going to happen, de Lima told CBC News in a rare interview in the blazing heat of Camp Crame, the compound housing the prison where she has been since her arrest last month.

As the only woman in the detention centre, which also houses the headquarters of the Philippine National Police, de Lima is segregated from the other roughly two dozen prisoners — some of whom she helped put away when she was justice secretary from 2010 to 2015.

Duterte's view is that she fits right in. Months ago, as she was calling for investigations into the extrajudicial killings that have been the hallmark of Duterte's reign since he came into power last June, she was charged with running a drug trafficking ring while justice secretary.

It's a stunning allegation — that the woman who was trying to hunt down corruption and drug crime was actually enmeshed in it. The pro-Duterte Speaker of the House, Pantaleon Alvarez, went further, calling her "public enemy No. 1" and "the No. 1 drug lord in the whole Philippines."

The essence of the accusation is that she allowed the drug trade to carry on at a local prison in exchange for kickbacks from drug lords. The charges could carry a life sentence if she's convicted. And there is no option for bail.

'I won't be quiet'

Exasperation isn't really an adequate word for how de Lima feels about all this.

"I have no connection to the drug world except going after them," she said. "Suddenly, I am the Pablo Escobar of the Philippines? Jesus, where is the proof? They can look and look — they will find nothing."

If the charges were an attempt to silence de Lima, they haven't worked very well. She seizes every opportunity to criticize Duterte.

"I will never accept the extrajudicial killings. I will never accept the violations of human rights," she said. "I won't be quiet."

Long before the charges were announced, Duterte vowed publicly to destroy de Lima. They have history. She has spent the better part of a decade trying to investigate allegations he was the leader of death squads while the mayor of Davao. In turn, he has persistently mocked and raged against what she says and does, and how she looks.

De Lima's cell is tiny. There's a small window, a few weights for exercise, some of her own clothes. It seems every available space is filled with the books and documents she now has the time to read. They help with the loneliness, she says, when she gets locked in just after 5 p.m. every night. Standing in that cell, she looks every bit the victim of politicized persecution that Human Rights Watch suggests she is.

Duterte's anti-drug campaign has enormous support in the Philippines. Since he launched a crackdown on crime and drugs after winning the presidential elections in July 2016, more than 7,500 suspects have been killed. (Dondi Tawatao/Getty Images)

A few times a week, religious leaders, Senate staffers and a few supporters show up for a mass intended just for her.

The group of about 17 bring roses and fresh orchids and rich cakes and try to squeeze in as many supportive words as they can before visiting hours are over. The mass is conducted under a small tent on the cracked concrete of a basketball court enclosed in barbed wire. Small fans have been pulled onto the court. Each one, on extension cords with extra extension cords, blows around the hot city air. A breeze yes, relief from the heat, no.

Her cell and a small bathroom are just off this courtyard.

On this day, the mass seemed to have a theme: the death of truth.

"Something is dying," declared one of the priests. "Language is dying. Truth is dying. Communication is dying. Social media is part of the crucifixion of language, slowly killing normal language. Justice is dying. Morality is dying. Democracy is dying. Love of country is dying."

Social media scorn

That mention of social media was hardly an idle one. The online world of the Philippines is an angry, reactive place. Duterte is immensely popular, and it is predominantly those who go after him who find themselves facing a barrage of venomous scorn, both from real people and from legions of bots and fake accounts. The vitriol can go both ways, though — extremes digging in while the idea of a moderate middle fades.

De Lima has been in the sights of Duterte's online defenders for a long time. They believe he is the tough change the Philippines needs and think de Lima is a dirty politician on the take. She has been a favourite subject of fake news published on bogus websites.

De Lima has been a favourite target of fake news stories, as in this composite of two headlines from two questionable websites: thet1mes.com and philmedia.info. (thet1mes.com/philmedia.info screengrabs)

"Incessant black propaganda and trolls and slut-shaming," de Lima says of the attacks against her, almost spitting out the words.

Her past relationship with a driver, who is also implicated in the alleged kickback scheme, was cooked into a scandal. Duterte told the nation there is a sex tape and he has seen it and it makes him sick.

That she admitted the past relationship has left her tainted in the eyes of many Filipinos who wonder aloud that if she could do that, then maybe, just maybe, she did all those other things, too. And then there is the testimony of convicted drug offenders implicating her.

"I'm not angry with them," she said. "I understand the pressures they are under to say those things.

"Those who know me know this drug nonsense is not possible. It didn't happen. But those who don't know me, then it seems they wonder."

Our conversation took place in small bursts between homilies, de Lima leaning in to occasionally whisper comments. It seemed at any moment guards might interrupt, but it didn't happen. They largely seem to leave the visitors alone.

"I know the truth: I am not at all involved in the illegal drug trade. I'm not a drug trafficker. I am not a drug coddler. Not at all guilty of the charges hurled against me," she said.

"Every day I am in detention is a day of injustice. You don't know how it feels to be falsely accused. I used to fight for victims of human rights abuses and oppression. Now that's me."

Asked if she had any message she wanted to send the outside world, she grabbed my notebook and scrawled these words: "Social media must stop being an instrument of lies, deceptions and oppression. Social media can truly be a powerful tool for change — genuine and positive change. Let's go back to basic human decency and civility and love."

De Lima scrawled a note for CBC News: "Social media must stop being an instrument of lies, deceptions and oppression. Social media can truly be a powerful tool for change — genuine and positive change. Let's go back to basic human decency and civility and love." (Adrienne Arsenault/CBC)

That feels pretty idealistic for the Philippines right now.

She believes her last resort is the Supreme Court. She calls it the last bastion of democracy and implores the judges to "go beyond the thoughts of pleasing the powers-that-be and just do their jobs." Her fear is that they won't take the risk of standing up to Duterte.

What she seems to be suggesting is: Look what happens to people who do.