A petition signed by Fudan University students pleading for clemency for a former medical student facing execution after poisoning his roommate has divided public opinion.

Signed by 177 students, the letter asks the Shanghai Higher People's Court to spare 28-year-old Lin Senhao, saying that life is precious and that China should phase out the death penalty.

While these sentiments have found support online, critics accuse the students of interfering with the judicial process as Lin has appealed against his sentence.

Lin was sentenced to death by the Shanghai No.2 Intermediate People's Court in February.

The Fudan postgraduate student killed roommate Huang Yang last year over a trivial grudge, putting toxic chemical n-nitrosodimethylamine into a water dispenser they shared.

Lin claimed during his trial that he had only intended to play an April Fool's prank on Huang, who died 15 days later

"Huang Yang has passed away. If Lin is executed, it will be a great loss to lose two young lives," said a petitioner and law school student surnamed Wang.

The petitioners also call for China to gradually remove the death penalty.

As a court is to hear Lin's appeal against his death sentence, some web users say the students are interfering with the law.

"I don't think it's their place to plead. If the verdict is overruled at the appeal, the public may think it was the petition rather than the law that saved the killer," Zhao Genming, a 50-year-old Shanghai resident posted online.

But Shanghai lawyer Yan Yiming said the court will consider numerous opinions, and the petition is one of many voices.

There is no date for the appeal yet.