"Following latest round of checkups, all of whom turned out to be normal, doctors agreed to discharge him on Thursday. However, it was later decided that he can be discharged this (Wednesday) evening," the PPP leader said on condition of anonymity.
"President Zardari will rest in Dubai for some more time and continue the heart medication," he added.
Zardari was discharged from the American Hospital, where he was admitted on December 6, and was expected to recuperate at his private villa in Dubai, Geo News channel reported.
A sizeable number of PPP workers and a large police contingent were present at the hotel.
There was no official word on Zardari's discharge or when he was expected to return to Pakistan.
Earlier in the day, presidential spokesman Farhatullah Babar had said Zardari was expected to be discharged from hospital on Thursday though he will have to continue to rest at home.
Babar quoted a health bulletin from American Hospital as saying that the results of all investigations conducted on Zardari were "within normal range".
The bulletin said the President had been advised to rest at home and to continue his "regular heart medications".
Religious affairs minister Khursheed Shah had said yesterday that the President would return to Pakistan in time for events to be held on December 27 to mark the death anniversary of his late wife, former premier Benazir Bhutto.