A bitter standoff between Prime Minister Nikol Pashinyan and the Armenian Apostolic Church has seen mass arrests, allegations of a coup plot, and an extraordinary offer by Armenia’s leader to reveal his private parts to prove he is a Christian.

Earlier this week, Pashinyan told his 1.1 million followers on Facebook he was prepared to expose himself to the head of the Armenian Church and his spokesman, to prove they were wrong that he had been circumcised.

Social media became his preferred means of communication after he came to office after Armenia’s so-called Velvet Revolution of 2018.

Pashinyan faces pivotal elections next year and the Church has become a prominent anti-government voice since Armenia was defeated in a 2020 war with neighbouring Azerbaijan.

His extraordinary offer last Monday followed a Facebook post by a priest in the southwestern town of Masis who alleged Pashinyan had been circumcised, comparing him to Judas and implying that he was not Christian.

“I believe that our Apostolic Holy Church must immediately cleanse itself,” said Father Zareh Ashuryan, “of those false ‘believers’ who have betrayed the nation, dishonoured the memory of their ancestors, violated the baptism, and replaced the seal of the Holy Cross with the sign of circumcision.”

The confrontation between Church and state began at the end of May when the prime minister accused the head of the Armenian Apostolic Church, Catholicos Karekin II, of breaking his vow of celibacy and fathering a child, demanding the church leader’s replacement.

The Church released a statement accusing Pashinyan of undermining Armenia’s “spiritual unity” but did not address the claim about the child.

Government-affiliated media subsequently circulated photos and names of Karekin II’s alleged daughter, while Pashinyan established a “co-ordination group” to organise the election of a new Church leader – despite constitutional provisions guaranteeing separation of Church and state.

When Karekin II returned from a trip to the UAE last week, hundreds of supporters gathered at Yerevan airport chanting Vehapar (Pontiff).

He called for unity and restraint, saying they would “overcome this difficulty” together.

The crisis then escalated on Wednesday, when security services detained 16 people, including Archbishop Bagrat Galstanyan, a senior cleric who leads the opposition Sacred Struggle movement. They face allegations of plotting terrorist acts to seize power.

Among the others detained are an opposition member, a former MP, a businessman and a blogger.

Armenia’s Investigative Committee alleges the group planned to establish 250 “assault” groups” of 25 members each to carry out attacks and cause mass disturbances, and that “a large quantity of items and objects intended for criminal activity” were found during the searches.

The archbishop led major anti-government protests last year and a court has now ruled that he should spend two months in pre-trial detention. He faces charges of planning terrorism and attempting to overthrow the state.

His lawyers have dismissed the allegations as “political persecution”.

The arrests followed the publication of what government-affiliated media claimed was a detailed opposition coup plan, allegedly involving the Church, recently detained Russian-Armenian billionaire Samvel Karapetyan, and two former presidents – Robert Kocharyan and Serzh Sargsyan.

Nikol Pashinyan shared a montage of the photos of the four men and said that the event would remain history as a “failed revolution of crooks”.

In a statement, Sargsyan’s Republican Party accused the government of using the “law enforcement system to silence political opponents”.

Samvel Karapetyan, who holds dual Russian and Armenian citizenship, is one of the richest men in Armenia, with an estimated wealth of $4bn (£2.9bn).

He owns the Tashir Group, known across Russia for its pizza brand. It is a conglomerate that operates real estate as well as the Electric Networks of Armenia – a major energy distributor in the country.

Karapetyan, one of the most prominent benefactors of the Armenian Apostolic Church and the recipient of high Church awards, was arrested after he made a public video pledging his support for the Church.

“I have always stood with the Armenian Church and the Armenian people. If the politicians do not succeed, we will intervene in our own way in this campaign against the Church,” he warned.

Hours after the statement, law enforcement officers conducted searches in Karapetyan’s mansion, he was arrested and later charged with publicly calling for the seizure of power.

He has denied all the charges against him.

Pashinyan’s spokesman suggested that the billionaire had decided to use a “classic manual received from the north” – a clear reference to Russia.

The prime minister later announced his intention to nationalise Karapetyan’s Electric Networks of Armenia (ENA) and he told a cabinet meeting on Thursday the government would start taking control of it.

“We must do this swiftly and effectively,” Pashinyan said.

Following Karapetyan’s arrest giant billboards with his photos appeared in Moscow – and Russia’s Armenian diaspora expressed support for the billionaire.

Russian foreign ministry spokeswoman Maria Zakharova said that Moscow was “closely monitoring” the situation around “Russian national Samvel Karapetyan” promising to provide him necessary assistance to ensure that his legal rights were respected.