Bangkok: Thailand’s premier on Friday threatened to prosecute anyone who criticised him or his government as the army detained a former lawmaker for ‘attitude adjustment’ after he slammed the junta’s economic policy.

In a sign the military is not easing its grip on dissent nearly 16 months after seizing power in a coup, former energy minister Pichai Naripthaphan and ex-MP Karun Hosakul — from the ousted Pheu Thai party — are being held for making critical comments on social media.

Reigniting the economy was among the junta’s main promises upon its takeover but what was once one of Southeast Asia’s most vibrant economies has remained limp.

‘This time I will not forgive him if he fails to understand. And if he repeats his actions then he will be prosecuted,’ army chief-turned-premier Prayut Chan-O-Cha told reporters in Bangkok about Pichai.

The former minister, detained for his seventh attitude adjustment session since the coup, had criticised the ruling junta’s economic plans on Facebook, suggesting his own ideas for reviving Thailand’s faltering economy.

Since the May 2014 coup scores of people have been required to attend attitude adjustment sessions, which are effectively a brief period of involuntary incarceration by the military that can last up to seven days.

Prayut, who is known for his mercurial outbursts, also warned critics against insulting him or the government.

‘All those who cause divisiveness or make groundless accusations against the government will face charges of inciting unrest and prosecution,’ he said.

‘Anyone involved in past mistakes should not speak out. Don’t oppose me,’ Prayut said before accusing ousted premier Yingluck Shinawatra’s government of damaging the country.

Thailand has been riven by bitter political rivalries for nearly a decade since Yingluck’s older brother Thaksin Shinawatra was deposed in a previous 2006 coup.

The Shinawatras have won every election since 2001 and the schism broadly pits them and their mostly rural and working-class supporters against Bangkok’s royalist elites, supported by large parts of the military and judiciary.

On Thursday Karun, a former Bangkok MP for Pheu Thai, was detained for ‘criticising the government unconstructively’, Prayut said, but he did not elaborate on the content of the criticism.

The junta chief’s comments come days after a military-appointed council rejected a controversial draft constitution.

Critics had said the charter was anti-democratic and aimed at prolonging military rule but its rejection has also pushed back the timetable for elections which are now unlikely before 2017.

According to iLaw, a local group that monitors arrest figures, more than 700 people have been ‘summoned’ by the authorities for attitude adjustment since the coup.