Lutf Amim Shibli, who once served as chairman of the Progressive Workers Union at the Karachi Port Trust (KPT), had begun his protest on November 1 outside Karachi Press Club (KPC), threatening that he would commit suicide if Gen(retd) Raheel was not given an extension in service.
"Raheel Sharif is a messiah. I am his fan. Only he can save the country from terrorism and social ills," read the posters and banners set up around his camp.
According to doctors, the man took his life by consuming poison a few days ago.
"He attempted suicide on November 27 after the ISPR [Inter-Services Public Relations] announced the retirement plan of Gen Raheel. We took him to Jinnah hospital from where he was referred to Aga Khan University Hospital. He was initially on ventilator, but later died," said Shibli's sister-in-law Nooren.
"Before consuming poison, he wrote a letter to his wife, saying that his funeral prayers must be held in front of the KPC," she was quoted as saying by the 'Express Tribune'.
Police surgeon Eijaz Ahmed said that Shibli's post-mortem had not yet been conducted but it looked he died of poisoning. Shibli's family originally belonged to Jalandhar, India, but they had migrated to Pakistan after independence and he joined the KPT.
He had married thrice and his first wife, Gulzari Begum, also a trade union leader of the Pakistan Steel Mills Progressive Workers Union, was killed a few years ago.
One of his close friends, while requesting anonymity, said the deceased was not mentally fit and would become aggressive on different issues confronted by Pakistan.
"He was frustrated and used to talk about committing suicide. Finally, he did it," he said.
Nasir Mansoor, deputy general secretary of the National Trade Union Federation, said Mr Shibli was a leftist leader and his decision to support the army bewildered many of his colleagues.
"We have never supported any general. I don't know how Shibi, who had once played a great role for the rights of labourers, became a fan of Raheel Sharif, which was unusual for left-oriented comrades," he said.
60-year-old Gen(retd) Raheel retired on November 29 after a three-year tenure. General Bajwa, 57, took over the command of the army on Tuesday at a ceremony in Rawalpindi from him.