In 1977 general elections, Zulfikar Ali Bhutto managed to return to power after he became the Prime Minister of Pakistan in 1973 (after the liberation of Bangladesh President Yahya Khan had resigned and Bhutto became Prime Minister).
PMLN candidates claim they have been ordered to defect from the party amid a systematic campaign of intimidation by agents of Pakistan's "deep state".
Recent nationwide polls indicate a tight race, with Khan's party ahead on 30 percent in one survey, compared to 27 percent for PML-N.
Khan, however, is wary of governing with the established parties.
Mr Gandapur had been informed about serious threats to his life and been provided with 11 policemen, but he did not inform the police about his political meeting on Sunday, Afridi said.
Many experts contend that it will be business as usual whoever wins the election, with the military - which has ruled the country directly or indirectly for much of its 71-year history - remaining Pakistan's de facto ruler.
Everywhere I go I find people basking into rapture saying that they would cast vote for PTI at any cast, and it would win.
Netflix and streaming service United Kingdom subscriber numbers overtake pay
More content is being watched on mobile devices, with 16-34 year olds leading the charge, Ofcom said. In 2017, the average daily viewing time was recorded to be three hours, 22 minutes.
Moeed Yusuf, a Pakistani analyst at the United Sates Institute of Peace, a Washington think tank, said: "I think you could have a complete collapse in terms of ability to form a government right after the election".
Of the 272 seats of National Assembly, elections will be held on 270 seats. A further 70 seats for women and minorities are awarded proportionally based on the voting percentages.
Voter turnout in the 2013 elections - won by the PML-N but without an outright majority - was 55%.
Nawaz Sharif himself has accused the generals of targeting his party, including intimidating his candidates to switch allegiances - particularly in Punjab province. He said the elder Sharif, along with his daughter Maryam Nawaz, were arrested and were not even allowed to meet Sharif's mother.
Hanif Abbasi, seen as a strong candidate for PML-N in Wednesday's poll, was sentenced in a rare late-night session Saturday.
The PTI chief, however, has deliberately ignored the Indian media during his campaign rallies, not to mention how he slammed the global media for raising reservations over the credibility of the upcoming general elections.
Sharif, 68, was removed by presidential decree in 1993, in a military coup in 1999, and a year ago by the Supreme Court, which ordered his corruption trial.