PSP chief Mustafa Kamal speaking to reporters at the Karachi Press Club welcomed the new member saying, "I welcome Irtiza to the party. I wish him all the best. I hope his addition proves beneficial for us and and all others who are just standing on the line waiting for a chance to join PSP."

Former Karachi mayor, Kamal, was flanked by Irtiza and other members of his party, which was born following a split from the MQM in March last year.

The defection is significant as political parties in Pakistan gear up for general elections scheduled in 2018.