Turkey's main opposition party said its Istanbul head was sentenced to nine years and eight months in prison on Friday mainly over social media posts, including "insults" to President Recep Tayyip Erdogan.
Canan Kaftancioglu of the secular Republican People's Party (CHP)'s Istanbul branch, was found guilty of "terrorist propaganda", among other charges, in a trial she has derided as political.
She played a key role in the shock victory of the CHP's new Istanbul mayor Ekrem Imamoglu earlier this year -- the first time Erdogan's party had lost power in Turkey's biggest city for 25 years.
The CHP said the sentences must be confirmed by an appeals court before Kaftancioglu can be sent to prison.
The tweets included criticism of the death of a 14-year-old boy who was hit by a tear gas grenade during the mass "Gezi Park" protests of 2013.
She received sentences for five charges, including 20 months for "humiliating" the state, 18 months for "insulting a public official", 28 months for "insulting the president", 32 months for "inciting the people to hatred".
Her "terrorist propaganda", for which she was given 18 months, consisted of quoting a member of the outlawed Kurdistan Worker's Party (PKK), which has been fighting a bloody insurgency against the state since 1983.