Pakistan's ruling party plans to pass long-delayed legislation against "honour killings" within weeks in the wake of the high-profile murder of an outspoken social media star, the daughter of Prime Minister Nawaz Sharif said on Wednesday.

The government has faced mounting pressure to pass the law against murders carried out by people professing to be acting in defence of the honour of their family.

The law would remove a loophole that allows other family members to pardon a killer.

A file photo of Maryam Nawaz Sharif (right) with her mother | Source: AFP

The brother of social media star Qandeel Baloch, often described as Pakistan's Kim Kardashian, has been arrested in connection with her strangling death and told a news conference he was incensed by her often risqué posts on social media.

Some 500 women are killed each year in Pakistan at the hands of family members over perceived damage to "honour" that can involve eloping, fraternising with men or any other infraction against conservative values that govern women's modesty.

Maryam Nawaz Sharif said the government wanted to pass the law unanimously and had been negotiating with religious parties in parliament. She said once the parliamentary committee approved the bill, it would be presented for a vote in a "couple of weeks" before a joint session of parliament.

A file photo of Qandeel Baloch | Source: Reuters

A spokesman for Jamaat-e-Islami, one of the two major religious parties in parliament, said his party would not oppose the bill.

Pakistan's other main religious political party, Jamiat Ulema-e-Islam, could not be reached for comment but it has only a small number of seats in parliament.

Both religious parties have traditionally opposed legislation empowering women.

The upper house of parliament passed the bill in 2014 but it lapsed after the government failed to put it up for a vote in the lower house because it was preoccupied with legislation aimed at tackling security problems and economic reforms.

A senior government official said all major parties were now backing the bill and it was likely to be passed in a few weeks by a joint session of parliament.

A file photo of Prime Minister Nawaz Sharif | Source: Reuters

"The prime minister is taking personal interest," added a second official and close aide to Sharif. "You will see in coming days more will be done, big changes will be announced."

In a rare move, this week the government became a complainant in the police case against Baloch's brother accused of her murder, designating it a crime against the state and thereby blocking her family from forgiving their son.

'Right to forgive'

Baloch had long divided opinion in the deeply conservative Muslim society with her social media photos and posts.

She was unapologetic about pushing the boundaries of acceptability for women and changing "the typical orthodox mindset" of Pakistanis. Many viewed her as a disgrace to the cultural values of Islam and Pakistan. Others hailed her as a "feminist icon". She ran into political controversy last month after her "selfie" photographs with a prominent Muslim cleric, went viral, leading to him being fired from a prominent Muslim council.

An ambulance carries the body of Qandeel Baloch | Source: Reuters

After her death, the cleric, Abdul Qavi, told media that her murder should serve as an example for others who tried to malign the clergy. He is being investigated for her murder along with Baloch's two brothers.

Although government officials appeared confident of backing for the bill in parliament, it could still face resistance. The influential Council of Islamic Ideology, which advises the government on the compatibility of laws with Islam, warned that it would not support any law that removed the forgiveness loophole, even though the council considers honour killings a crime.

"Islamic law and the Koran say that the right to forgive or punish lies first and foremost with the victim's family. So if this bill is trying to completely take away that right from the family, then of course that is against Islamic teachings. The state cannot completely take away that right from the family," said council spokesman Inam Ullah.

Wasim (R), the brother of slain social media celebrity Qandeel Baloch, is escorted by police following his arrest for Qandeel's death in Multan | Source: AFP

The religious parties and the council hold significant influence over public opinion and the government fears a backlash if any law passes without their approval.

"This mentality - that you can get away with murder in the name of honour - it has to be done away with," said Sharmeen Obaid-Chinoy, whose documentary on honour killings "A Girl in the River: The Price of Forgiveness" won an Oscar this year.

"I am hopeful that this law will pass but the change in mindset will talk so much longer ... I think Qandeel Baloch's murder is the tipping point."