PML-Nawaz President Shahbaz Sharif on Thursday demanded the Election Commission of Pakistan (ECP) to ensure the conduct of free and fair elections in the country.

"Discriminatory action against the candidates of political parties during their election campaign is undesirable," Shahbaz said, days after Raja Qamarul Islam — the PML-N candidate contesting on a national and a provincial assembly seat against N-league's disgruntled leader Chaudhry Nisar Ali Khan — was arrested by the National Accountability Bureau (NAB).

"NAB's action has raised questions on the fairness of the election process," he said in a statement released to media, expressing concern over Islam's arrest.

He alleged that the "revenge tactics" adopted by NAB were an attempt to damage the PML-N's election campaign, adding that his party has "always presented itself for accountability".

The former Punjab chief minister said the PML-N has approached the ECP in accordance with Article 218(3) of the Constitution and was hoping the commission would take action to ensure free and fair elections.

"PML-N thinks the disqualification of its candidates, and those of opposing parties, is not correct," Shahbaz said, a day after former prime minister Shahid Khaqan Abbasi was disqualified from the NA-57 election by an election appellate tribunal — a move he has since challenged.

Earlier in the day, PML-N leader Daniyal Aziz was also disqualified for five years after being found guilty of contempt of court.