ANKARA - As his family and friends huddled around a speaker, the jailed presidential candidate of Turkey's pro-Kurdish opposition called home from his prison cell on Wednesday for his first election "rally" ahead of June 24 elections."For 20 months, I have been held here under an illegal, unjust and unlawful decision as a political hostage," Selahattin Demirtas, the former leader of the Peoples Democratic Party (HDP), told his supporters."Moreover, while my hands are tied, the everyday slander campaigns of government officials against me continue on televisions without a break," he said in a video clip posted by the HDP on Twitter. It was shared more than 10,000 times.Demirtas, one of Turkey's best-known politicians, has been jailed pending trial for a year and a half over terrorism charges and faces up to 142 years in prison if convicted. He denies the charges."Today the whole country, all our citizens, have become victims of injustice," Demirtas said. "Turkey as a whole has unfortunately been turned into a prison."Since an abortive military coup in 2016, some 160,000 people have been detained and nearly the same number have been dismissed from their jobs, the United Nations said in March.President Tayyip Erdogan's government says the detentions and dismissals are necessary to safeguard national security.ERDOGAN TIPPED TO WIN AGAINErdogan is strong favorite to win re-election to a newly empowered executive presidency in this month's election, though his Islamist-rooted AK Party is in a close race with the opposition for parliamentary polls also being held on June 24.On Tuesday, in some of his harshest comments yet, Erdogan called Demirtas a "terrorist" and said his candidacy in the presidential election was "not proof of his innocence."Erdogan and his government accuse the HDP of links to the outlawed Kurdistan Workers Party (PKK), which has waged a decades-long armed insurgency against the Turkish state in which more than 40,000 people have been killed.The HDP, which says up to 5,000 of its members have been detained in the latest crackdown, denies any militant links.Demirtas accused the Turkish government on Wednesday of trying to establish an "empire of fear" and said the country was "being shattered."In previous elections, Demirtas won votes beyond his core Kurdish constituency, and he is likely to draw significant backing in the first round of the presidential vote, while boosting the prospects of his party entering parliament.Pollster SONAR said on Tuesday that Erdogan would fall short of winning a big enough majority to win the presidency in the first round, forcing a second round in early July that he would win with 53 percent.In the parliamentary election, the HDP is seen winning 10 percent, the threshold needed to enter parliament, SONAR said.Demirtas has had to run the bulk of his campaign through social media from his prison cell in the northwestern Turkish city of Edirne, while Turkish media have been saturated with coverage of Erdogan and his ministers."Demirtas isn't the one being kept in a cell in Edirne, it is you. Trust yourself. Honor yourself," he said, as his family and friends applauded and cheered in the living room of his home in Diyarbakir, in mainly Kurdish southeast Turkey.