Mirza is considered to be the right-hand man of President Asif Ali Zardari. He had earlier accused the MQM of extorting money from citizens of Karachi. He also alleged MQM’s involvement in unending killings in Karachi.

"I am not going to remain silent," he said. "I will spill the beans. I have not surrendered to MQM’s blackmailing. Being a leader of the PPP (Pakistan People’s Party) I will now expose the crimes of the MQM."

MQM leader Wasim Akhtar said the issue was an internal PPP matter.

"We want to co-habit peacefully," he said. "Our efforts remained to bring peace in Karachi."