A joint sitting of the Senate and the newly elected national and provincial assemblies — together known as the electoral college of Pakistan — will elect the country's new president via a secret ballot on Tuesday, according to Pakistan Dawn News report.

In the running for the post are Dr Arif Alvi of the ruling Pakistan Tehreek-i-Insaf (PTI); PML-N backed chief of the Muttahida Majlis-e-Amal (MMA), Fazlur Rehman; and senior PPP leader Aitzaz Ahsan.

Pakistan’s Constitution requires the presidential election be held at least a month prior to the outgoing president's final day in the office – which should have been on August 9. Incumbent President Mamnoon Hussain’s term ends on September 9.

However, since the electoral college was not complete by the Constitutionally set deadline, the presidential election was subjected to delay and scheduled for Tuesday, September 4.

The presidential election will be held simultaneously at the Parliament House, Islamabad and the four provincial assemblies between 10am to 4pm local time, Dawn News reported.