The opposition leadership should now disclose the date, month and year when their members would tender their resignations from the assemblies, he added.
The Pakistan Democratic Movement (PDM) chief was formally invited by former President Asif Ali Zardari during their telephonic conversation.
On behalf of Fazlur Rehman, a five-member delegation of the party including Abdul Ghafoor Haideri, Siraj Ahmed Khan, Abdul Razzaq and Saud Afzal will attend the rally.