Sombat Boonngam-anong, speaking to an Associated Press reporter at a prison in Bangkok's northern outskirts, also had some words for the ruling military: don't expect to achieve reconciliation among the country's sharply polarized people by continuing to suppress free speech.
Sombat, 46, is a veteran social activist who used social media to spearhead the "Hunger Games''-inspired three-finger salute campaign to protest the May 22 coup, even as he was in hiding.
"The more that protesters keep up overt resistance, the longer it will give an excuse for the military to keep martial law in the country,'' Sombat said on Thursday.
He had to shout through a window to speak to his prison visitors, so his voice was hoarse and he had to pause briefly a few times as he was interviewed. It was not clear if he felt he could speak frankly.
Sombat was arrested on June 5 in eastern Thailand after being one of a handful of people - among hundreds summoned - to defy an order to report to the military authorities.
Under regulations imposed by the military, people who do not report in as ordered are subject to prison terms of up to two years and a fine of 40,000 baht ($1,250). They are also threatened with up to seven years in prison under an existing statute against causing public disorder. Sombat's political activity leaves him open to additional charges as well, including under a broadly defined law covering online activity.
Sombat was captured after organizing groups of demonstrators to come together on Sundays for peaceful anti-coup protests despite a ban on political gatherings of five people or more. The numbers of protesters have now dwindled in the face of a massive show of force by police and soldiers.
"My message for supporters is that now that the coup is a done deal, they should stop their resistance and instead focus on the issue of transparency for the junta's actions. Promote more checks and balances for their projects,'' Sombat said.
The junta has announced a raft of measure that it says will fight corruption and cronyism and clean up society. Some of their proposals involve massive spending, and with no legislature in place, there is no oversight.
The coup came after months of sometimes violent protests demanding that Prime Minister Yingluck Shinawatra make way for an appointed government to institute reforms and remove her powerful family's influence from politics. Although the army said it stepped in to curb violence, its agenda is nearly identical to that of the protesters.
Like other detainees, Sombat was first held at an army camp, where he was interrogated and told the military's line on political developments.
"They came to talk to me a lot and asked a whole host of questions to see whom I have contacted and what kind of activities I was doing,'' Sombat recalled.
"I agreed with the soldiers about the part about the conflict, that the country was divided and that it could turn out badly,'' he said. "What I don't understand is how they think there could be reconciliation when they haven't allowed anyone to speak freely.''
The army closed down many television and radio stations, allowing them to reopen only on the condition they do not broadcast controversial political material. Newspapers face the same restrictions.
"No matter what, you have to open up for participation from people from every level and every side. People need to talk. Reconciliation cannot succeed if you don't allow people to talk openly,'' Sombat said.
Sombat was one of the first people to organise protests against Thailand's previous coup, in 2006, and became known for his imaginative and non-violent tactics. He was loosely associated with the red-shirt movement, which supported Thaksin Shinawatra, who as caretaker prime minister was ousted in 2006, and more recently his sister Yingluck Shinawatra, who was forced out of office by a court ruling last month slightly ahead of the coup.
Sombat's first 12-day detention period ends Monday and he may ask for temporary release, although another arrest warrant involving allegations of anti-monarchy comments - which could carry 15 years' imprisonment - means his time in prison might be prolonged.