The intervention of Pakistan's prime minister has apparently led prosecutors to drop murder charges against the owners of the Ali Enterprises factory, where a fire killed around 249 garment workers in September last year.

Raja Pervaiz Ashraf's intervention follows a meeting with business lobby group the Karachi Chamber of Commerce and Industry (KCCI) at a function at the end of December.

The KCCI argued that the owners should not face pre-meditated murder charges as no industrialists or business people "would purposely destroy his own factory and commit murder of his own workers and it is also not according to the law."

The KCCI claims the prime minister did not recommend that the charges be withdrawn, but instructed the chief secretary of Sindh province to revisit the case to "ensure the application of premeditated murder was correct".

According to media reports, around 1500 workers were in the underwear factory when the fire broke out. Many victims were trapped in a basement with no fire exits and locked doors. Most died from suffocation when the basement filled with smoke. Other workers on higher floors rushed to windows to escape but struggled to get out because metal bars blocked their way.

According to the global union federation Industriall, the National Trade Union Federation (NTUF) in Pakistan and other labour rights organisations have filed petitions against the owners of Ali Enterprises.

Industriall emphasised that the court has to hear all the petitioners in the matter before delivering its judgement.

If the court delivers a ruling modifying the charges, petitioners are able to appeal, which NTUF and other labour rights organisations say they are considering.