The former Georgian president Mikheil Saakashvili says he is the victim of an international plot to “squeeze” him out of Ukraine, where he has emerged as a vocal critic of the country’s president, Petro Poroshenko.

A court in Kiev, the Ukrainian capital, rejected on Monday Saakashvili’s appeal for protection against possible extradition to Georgia, where he is ruled to have illegally pardoned in 2008 four police officers accused of murder. The Ukrainian court ruling came a month after a judge in Tbilisi, the Georgian capital, sentenced him to three years in jail in absentia.

Saakashvili, who ruled Georgia for nine years until 2013, denies the charges, and alleges that the extradition request and prison sentence were orchestrated jointly by Poroshenko and the former Georgian prime minister Bidzina Ivanishvili, a billionaire businessmen and political foe.

“The Georgian authorities never asked for my extradition when I was in America or in Europe,” said Saakashvili, 50, during an interview at the offices of his Movement of New Forces opposition party in central Kiev, a short walk from Ukraine’s parliament. “They only did it when I returned to Ukraine because Poroshenko asked them to.”

He alleged that the Kiev court’s decision to reject his appeal against extradition came after Ukraine had “begged” several European countries to take him. “The countries said: ‘Yes, fine, we can take him, but he has to make a formal request.’”

The Ukrainian justice minister, Pavlo Petrenko, denies that the extradition proceedings against Saakashvili, who is currently stateless, are politically motivated.

Poroshenko, who was elected president in 2014 after a revolution that toppled Ukraine’s Moscow-friendly leader, Viktor Yanukovych, appointed the fiery Georgian-born politician as the governor of the Black Sea region of Odessa in 2015.

But Saakashvili resigned as Odessa’s governor in November 2016 in protest at what he said was ingrained high-level corruption and launched a campaign to oust Poroshenko. In July, Poroshenko stripped Saakashvili of his Ukrainian citizenship while the former Georgian leader was in the US. “Poroshenko hoped that I wouldn’t try to come back to Ukraine,” said Saakashvili.

In an audacious move, Saakashvili was in September bundled over the border into Ukraine by hundreds of supporters. In December, he was dragged from the roof of his apartment by masked security service agents only to be freed shortly afterwards by a crowd of opposition activists amid chaotic scenes.

“I thought they were sending me back to Georgia. I went on to the roof because that was the only place my cellphone would work. They were jamming it inside the apartment,” Saakashvili said.

He was later rearrested and charged with involvement in a Russian-backed plot to destabilise Ukraine, an accusation that Saakashvili, a longtime Kremlin critic, dismisses as politically motivated “lies”. A judge in Kiev rejected the prosecutor’s arrest to place him under house arrest, however, ordering him instead to observe a nightly curfew that expired on Tuesday. On 17 December, Saakashvili led several thousand people on a protest that resulted in brief clashes with security services in the Ukrainian capital. He also headed a similarly sized rally on Sunday to call for Poroshenko’s impeachment.

Saakashvili alleges his Georgian bodyguards, friends and supporters have been kidnapped by Ukrainian security services, tortured, and deported to Georgia in recent months: “They were seized at home, put on an security service bus and put on a special flights or ferries to Georgia.”

Ukraine’s human rights ombudsman, Valeriya Lutkovska, said in November that three Georgian citizens with ties to Saakashvili had been illegally deported without a court order by Ukraine’s national police.

Although opinion polls indicated that Saakashvili was Ukraine’s most popular politician during his governorship of Odessa, with approval ratings of over 40%, his ratings have slid to less than half that figure since his resignation. Poroshenko, who many Ukrainians say has betrayed the country’s 2013-14 revolution, also has approval ratings of around 15%.

“It will be a big problem for the Georgian and the Ukrainian authorities if I am extradited,” Saakashvili said. “There will be a huge outcry, huge protests in Ukraine. This is not just about me; this is about injustice. And Ukrainians hate injustice.”