"Asif Ali Zardari had a hand in the disqualification of Nawaz Sharif, and today's decision is also according to his wishes," Akram Sheikh, a lawyer for Sharif, told reporters after the verdict.
With this verdict, ruling party is set to struggle in the country's richest and most populous province, Punjab, where Sharif's party currently governs in coalition with that of Zardari.
The court has also dismissed the election of Sharif's brother, Shahbaz Sharif as 'null and void' to a seat in the Punjab Assembly. That means Shahbaz Sharif cannot continue as head of the provincial government.
The brothers appear unlikely to ask the Supreme Court to review its decision. They have refused to appear before it in person and cast doubt on its legitimacy to hear the case.