ISTANBUL (Reuters) - Turkey’s top appeals court approved a jail sentence against a lawmaker from the pro-Kurdish Peoples’ Democratic Party (HDP) on terrorism charges, state media said on Friday, potentially opening the way to him being barred from parliamentary membership. Two other lawmakers from the HDP, the parliament’s third largest, had their parliamentary status revoked last year, after convictions against them became final. Revocation of their status means they are no longer a member of the assembly. President Tayyip Erdogan, his AK Party and their allied Nationalist Movement Party (MHP) accuse the HDP of links to the outlawed Kurdistan Workers Party (PKK). HDP denies links to terrorism. Many of the party’s prominent members have been investigated, tried and jailed over terrorism charges. Selahattin Demirtas, the party’s former leader and one of Turkey’s most prominent politicians, has been in jail for more than four years. The HDP has came under renewed pressure this week after 13 captive Turks were found to have been killed by PKK militants in a cave in northern Iraq. State-owned Anadolu news agency said on Friday the Court of Cassation approved a jail sentence of two years and six months against HDP lawmaker Omer Faruk Gergerlioglu over spreading terrorism propaganda. The ruling means the sentence is final, which could lead to his parliamentary status being revoked. Another investigation was launched against Gergerlioglu this week after he said on Twitter that the Turks who were killed by the PKK could have survived if the government had made efforts to rescue them. The PKK, designated a terrorist group by Turkey, the United States and European Union, has been waging an insurgency in the mainly Kurdish southeast Turkey since 1984 and more than 40,000 people have been killed in the conflict. Turkey’s recent fight against the PKK has increasingly focused on northern Iraq, where the group has its stronghold in the Qandil mountains.