Senior MQM leaders, including Hyder Abbas Rizvi, Farooq Sattar and Faisal Sabzwari, described the rally as the biggest-ever in the history of Karachi and Pakistan.
"Today those follow and love Altaf Bhai have created a record because never before has such a massive rally been held in Karachi," Sattar claimed.
Rizvi said: "Our rally will prove Altaf Hussain is the only leader who people trust the most". He said Hussain had laid the foundation of ideological politics in Pakistan and given a platform to the downtrodden and middle-class to represent the people in the Parliament.
"How come when no charges have been laid out or proven, bank accounts of our leader and party are being frozen and they are being harassed? We respect the law but it should not be used to try to pressurise Altaf Hussain from playing his role in Pakistan politics," he said.
MQM is the single largest party in Karachi and has dominated the political landscape of urban areas in Sindh province since the late eighties.
The MQM chief, who has millions of supporters, does not even live in Karachi. For over 20 years, Hussain has operated from the north London suburb of Edgware, beyond the reach of Pakistani prosecutors.
He has been accused of inciting murder and violence in his home country.
