The ballots will be cast for 272 general seats of the lower house -- also known as the National Assembly -- and 577 general seats of the country’s four provincial assemblies.

Around 50 political and religious parties are taking part in the elections, which have been marred by allegations of “manipulation” and “engineering”; the main contest is expected to be between three mainstream political parties and a five-party religious alliance.

The fieriest part of the race is expected to be between the two right-wing parties -- the Pakistan Muslim League (PML-N) of three-time Premier Nawaz Sharif, who is currently in jail following a corruption case verdict against him, and the Pakistan Tehreek-i-Insaf (PTI) led by former cricket star Imran Khan.

Pakistan Peoples Party (PPP) of slain prime minister Benazir Bhutto, and religious alliance, Muttehida majlis Amal (MMA) are also in the run.

According to surveys held by Pakistani think tanks, a neck-to-neck contest is expected between the PML-N and the PTI.

In Punjab, the country’s most populous province and political power base, PML-N stands ahead of PTI with 51 percent votes; however, PTI, which enjoys the support of 31 percent votes, is quickly gaining ground, the surveys conducted by think tanks, Gallup Pakistan and Pulse, revealed.

In northwestern Khyber Pakhtunkhwa province, PTI appears to be the most preferred choice with 57 percent votes followed by the religious parties’ alliance, MMA, and the PML-N, the surveys said.

Pakistan Peoples Party (PPP), led by slain former Premier Benazir Bhutto’s widower and son, enjoys the support of 44 percent votes in southern Sindh province, whereas in southwestern Balochistan, there is a mixed support for PPP, MMA and the PTI, it added.