Pakistan's Supreme Court issued a contempt notice to Prime Minister Yusuf Raza Gilani on Monday, ordering him to appear before the court over failure to prosecute government officials in long-running corruption cases.
The move escalates the pressure on Pakistan's weakened civilian government, which faces separate court procedures that could unseat its leadership and force early elections at a time of soaring tensions with the powerful army.
"The Supreme Court has issued a contempt of court notice to the prime minister for not complying with its orders," Judge Nasir-ul-Mulk told the court which met to debate how to proceed on graft charges against the president.
"He has been directed to appear personally on January 19," the judge added.
"In these circumstances, we are left with no option, as a first step, to issue a show cause notice," the notice issued by the seven-member bench stated.
The Supreme Court wants the government to write to Swiss authorities demanding that they re-open old corruption cases against President Asif Ali Zardari, which the government has so far refused to do so.
Zardari and the government led by his Pakistan People's Party (PPP) say he has immunity from prosecution as long as he remains in office.
The president is also under pressure from an investigation into who was behind efforts to solicit American help to prevent a coup apparently feared in the aftermath of Osama bin Laden's death and to clip the power of the army.
Zardari's close aide, Husain Haqqani, was forced to resign as ambassador to Washington over a secret memo written last May and the Supreme Court ordered an inquiry on December 30 following a demand from the country's chief spymaster.
"The prime minister should appear personally in court on Jan. 19."