"The economic policies pursued by President Musharraf during the past eight years have brought Pakistan to the brink of critical economic impasse," he said.

"His policies have weakened the federation and eroded the trust of the nation in national institutions."

In his speech to the press, Zardari warned Musharraf against dismissing parliament in a bid to avoid the impeachment proceedings.

Agreement reached

The coalition had previously been split by the twin issues of what to do about Musharraf and how to carry out their pledge to reinstate senior judges sacked by him under emergency rule last year.

But officials said an agreement was reached on Wednesday night, when Nawaz Sharif, leader of the Pakistan Muslim League-Nawaz (PML-N) party, assured Zardari that he could count on the support of former PML-N members who currently belong to a pro-Musharraf party.

There was no immediate response from the president's office but Kamal Hyder, Al Jazeera's correspondent in Islamabad, said there was still a little way to go before the president was censured.

"Many people across the country believe it's not going to be that simple and the process of impeachment will be a complex one," he said.

"The president still has a few tricks up his sleeve."

Impeaching a president would require a two-thirds majority in both houses of parliament and Musharraf loyalists maintain the coalition would struggle to muster enough support.

Earlier in the day, as the deal to impeach Musharraf emerged, the president cancelled his trip to the Beijing Olympics.