Turkish Constitution Court meeting regarding "367 quorum" started on Tuesday afternoon. The court has been urged to reject an opposition challenge to the presidential election that has split Turkey.
The Constitutional Court is due to rule by Wednesday on a request by the main secular opposition party to suspend the election. The opposition accused the Islamist-rooted government of carrying out an illegal vote in parliament last week.
Suspension could trigger an early general election and, in the view of many analysts, help defuse escalating tensions between secularists, including the army, and the government.
The court's rapporteur -- who acts as a prosecutor in such cases -- Hikmet Tulen had recommended the bid by the Republican People's Party (CHP) be rejected.
The recommendation is not binding. The court started deliberating on the challenge at 2 pm (1100 GMT).