Supreme Court of Pakistan on Tuesday disqualified syed Yousuf Raza Gilani as prime minister in a stunning move throwing the country into fresh turmoil just months before expected general elections.A three-member Bench of the Supreme Court made the move after it had sentenced and convicted Gilani on April 26 of contempt of court for refusing to write to Switzerland for reopening multi-million-dollar graft cases against President Asif Ali Zardari."Yousuf Raza Gilani has become disqualified from being member of the parliament," said the order read by chief justice Iftikhar Muhammad Chaudhry."He has also ceased to be the prime minister of Pakistan with effect from the same date (April 26) and office of the prime minister shall be deemed to be vacant accordingly," it said."The president of Pakistan is required to take necessary steps under the constitution to ensure continuation of the democratic process through parliamentary system of government in the country," Chaudhry read.President Zardari has convened meeting of the heads of coalition parties to the presidency for further talks at 9pm today.Gilani, Pakistan's first sitting prime minister to be convicted, has faced down widespread calls from the opposition to quit.He has insisted that only parliament can remove him from office.Under the constitution, anyone convicted of defaming or ridiculing the judiciary is barred from being an MP. Experts opine that Syed Yousuf Raza Gilani is also disqualified for five years to become member of the parliament after conviction for contempt of court. The matter of disqualification fell first to the speaker of parliament, Fehmida Mirza, a member of the PPP who on May 24 said conviction for contempt was not a charge that meant he should be disqualified under the constitution.Gilani subsequently decided not to appeal against his conviction understanding that the Speaker's ruling was final and unchallengeable before the Court. But senior opposition politicians, including Imran Khan and former prime minister Nawaz Sharif, challenged the ruling.The allegations against Zardari date back to the 1990s, when he and his late wife, former premier Benazir Bhutto, are suspected of using Swiss banks to launder $12 million allegedly paid in bribes by companies seeking customs inspection contracts.The Swiss shelved the cases in 2008 when Zardari became president.Gilani has always insisted Zardari has full immunity as head of state and last month said that writing to the Swiss would be a violation of the constitution.He was briefly -- but symbolically -- held in the courtroom for his sentence, which ended as soon as the judges arose for the day after announcing the verdict.