A full bench of Lahore High Court, chaired by Chief Justice Ijaz Ahmed Chaudhry, heard the petition.

The petitioner’s lawyer, A.K. Dogar, said under the constitution of Pakistan, the president could not hold two offices.

Delivering a 37-page verdict, the court said the president should perform his duties with “neutrality, impartiality and aloofness from any partisan/political interests.” It said that the president must “dissociate himself from the political office” as quickly as possible.

Most other presidents in Pakistan have not been party leaders.

Zardari’s lawyers boycotted the court proceedings.

Dogar submitted to the court that due to his bad reputation, Zardari was not eligible for the post of the country’s president as per Articles 62 and 63 of the constitution. He said that there were several allegations of corruption against Zardari.

Zardari holds the right to move the Supreme Court. Before the top court admits the president’s appeal, Zardari’s political activities have been legally banned.

Farahnaz Ispahani, a spokesperson for Zardari, said she had not seen the ruling and could not comment.

The president could choose to ignore the ruling or appeal it, which could stretch out the proceedings for many more months. His term ends in 2013.

Opposition party members urged him to step down immediately, according to local television reports.