The Pakistani Justice Party was the forerunner of the Tehrik-e-Istiqlal party of Asghar Khan.
The old Justice Party had links with old Pakistan National Party (or the current National Party, NP) and the oldest Pakistani "Social Democratic" party formed in 1975 called the Pakistan Democratic party (PDP) which eventually along with some PPP-SB factions emerged with the PTI led by Imran Khan.
References
Justice Party (Pakistan) Wikipedia(Text) CC BY-SA