The Supreme Court has been asking the government to write to the Swiss to re-open the cases since late 2009 when it revoked a political amnesty freezing legal proceedings against key politicians.
A seven-member bench headed by Justice Nasir ul Mulk directed the attorney general to communicate the order to Prime Minister Yousuf Raza Gilani.
The prime minister shall comply by writing to the Swiss to reopen the cases and submit a report by March 21st, the court said.
It was understood to be the first time the Supreme Court has asked the prime minister directly. In the past, demands were conveyed through the law ministry, which could add its own advice.
On February 13th, Gilani was charged with contempt over the government's refusal to write to the Swiss. If found guilty, he could be jailed for six months and disqualified from office.