Congo's electoral commission has filed an election postponement request to the constitutional court, formally confirming that the Nov. 27 date for the presidential vote will be missed.

Commission president Corneille Nangaa said the commission filed the request Saturday because voter lists will not be ready for the Sept. 20 start of the election period.

The commission did not propose a new election date.

Election officials have said lists will not be ready until July 2017. Many fear unrest over the uncertainty.

Opposition leaders have said a delay is meant to keep President Joseph Kabila in power after his mandate ends in December.

Congo's justice minister has suggested that the ruling party and opposition could share power in an interim government, given the delays.