ISLAMABAD — The government of Raja Pervez Ashraf Wednesday told the Supreme Court that it will not reopen an old corruption case against President Asif Ali Zardari. In doing so the government has defied a judicial order that has brought down one prime minister and threatens his replacement. The crisis has roiled Pakistan's political system for months, distracting attention from what many Pakistanis believe are more pressing problems, such as the country's ailing economy and fight against the Taliban. The dispute centers on a graft case against President Zardari dating back to the late 1990s in Swiss court, a time when he became known as “Mr. 10 percent” for his reputation of demanding kickbacks on government contracts. The court has demanded the government write a letter to Swiss authorities asking them to reopen the case. The government has refused, saying Zardari enjoys immunity from prosecution while in office. The court convicted former prime minister Yousuf Raza Gilani of contempt and ousted him from office in June for refusing to write the letter. The ruling Pakistan People's Party rallied support to elect a new premier and has remained defiant. Attorney General Irfan Qadir told the judges Wednesday that Prime Minister Ashraf also refused to reopen the case because of the president's immunity. “Your order is not implementable,” said Qadir. He accused the lead judge, Asif Saeed Khosa, of being biased against the president and said he should recuse himself from the proceedings — a demand rejected by Khosa. Many government supporters have accused the Supreme Court of relentlessly pursuing the case because of bad blood between Zardari and Chief Justice Iftikhar Mohammad Chaudhry. Khosa demanded the new prime minister write the letter to the Swiss, but also seemed to soften the court's stance, saying the judges would respect the president's immunity if the government obeyed their order. He also gave the government more time to come up with a solution. Wednesday was the initial deadline for the government to say whether it would fulfill the court's order, but Khosa adjourned the hearing until Aug. 8. The judge's somewhat softer stance could be a reaction to criticism of the court for threatening to bring down the first civilian government poised to finish its five-year term in the country's history. Past governments were toppled by direct or indirect intervention by the powerful army, often with the help of the judiciary. The current government's term ends in early 2013. — Agencies