Haroon Sultan is contesting against a female candidate, reportedly his sister-in-law. (Representational)

Pakistan Muslim League-Nawaz (PML-N) candidate for the July 25 general election and former Punjab province minister Haroon Sultan has sparked a controversy by terming it "haram" to cast votes for women.

Haroon Sultan, who has served as minister for social welfare in the previous tenure of the PML-N government in Punjab, is contesting elections from the National Assembly constituency NA-184 against Pakistan Tehreek-e-Insaf's female candidate Zehra Basit Sultan Bukhari, who is also reportedly his sister-in-law.

Addressing a rally in his constituency in Muzaffargarh, Haroon Sultan said he will follow the directions of religion and will abstain from casting a vote to any female candidates as it is considered "haram" (forbidden in Islam), The News reported.

"I will work under the commands of Allah and His messenger...and will desist from doing the contrary," he added.

Pakistan People's Party has fielded Nawaz Iftikhar Khan in this constituency.

PML-N is led by former prime minister Nawaz Sharif, who was disqualified by the Supreme Court last year in the Panama Papers case.

Voting is a constitutional right in Pakistan, but millions of women have been prevented from exercising their franchise by men using outdated customs.