Weeks of sit-in protests by supporters of Qadri and opposition politician Imran Khan reached a climax in early September 2014 as protesters clashed with police and stormed the state broadcaster.
For a few hours it looked as if Prime Minister Nawaz Sharif's government might fall, but the crisis abated and eventually the protesters went home.
Qadri, a mercurial figure who also brought Islamabad to a standstill with mass protests in early 2013, wanted Sharif to resign and demanded sweeping changes to the country's political and welfare system.
Thousands of his followers of all ages gathered in two vast compounds in the eastern city of Lahore to pray, fast, sleep and eat together.
The 64-year-old began leading the annual vigil in Lahore three decades ago and it formed the basis of his Pakistan Awami Tehreek (PAT) political movement, founded in 1989.
He describes the event as "an exercise to discipline the followers for a revolution to run the country in the lines of the system introduced by the holy Prophet Mohammed 14 centuries ago".
When the protests were going on, some -- including members of Sharif's ruling PML-N party -- accused him of being a puppet, working on behalf of the powerful military to try to destabilise the elected civilian government in a bid to increase the generals' influence.
Qadri would not address the allegation directly but condemned his critics in general terms.
"There have always been opponents. There were opponents of the prophets. The opponents always propagate negatively and I can't come to their level to answer their propaganda," he told AFP.