Article published on the 2008-08-07 Latest update 2008-08-07 13:20 TU
Zardari, who is former Prime Minister Benazir Bhutto's widower, told a press conference that "it has become imperative to move for impeachment".
He said that the coalition will draw up a charge sheet against the President and that proceedings will be launched.
"The measures taken by President Musharraf over the last few years have brought Pakistan to a critical economic impasse," said Zardari, adding that Musharraf "has worked to undermine the moves to democracy".
Flanked by Sharif, he announced that all the judges removed by Musharraf will be reinstated and said that the Muslim League would rejoin the cabinet, which it quit in May because of failure to take the measure.
The lower house of parliament has been summoned to meet on 11 August, although it is not yet clear whether impeachment proceedings will begin then.
Musharraf cancelled his plan to go to the opening of the Beijing Olympics, having reversed an earlier declaration that he would not go on Wednesday. Prime Minister Yousuf Raza Gilani will represent the country there.
Islamabad correspondent Rana Jawad told RFI that Musharraf's allies say that will not leave without a fight.
"Either he will impose direct presidential rule through and emergency order or he will dissolve the National Assembly and bring up a caretaker setup to run the affairs of the government," he says.