A combative Pervez Musharraf [Images] on Monday vowed to slug it out in the Pakistan Parliament, which began its crucial session as the ruling coalition got ready to impeach him for alleged misconduct, violation of the Constitution and financial irregularities.

Ignoring mounting pressure from both friends and foes to quit before the National Assembly initiates the impeachment process, Musharraf said he would prove "false before the nation" all the allegations levelled against him by the ruling coalition.

The session of the 342-member Assembly commenced on Monday evening as the Paksitan People's Party-led coalition said it has drawn up an "unimpeachable" chargesheet listing allegations of misconduct, violation of Constitution and financial irregularities against Musharraf, who turned 65 on Monday.

"It will be an unimpeachable document supported by documentary evidence of all the acts of omission and commission committed by Musharraf that make him liable to impeachment several times," PPP spokesman Farhatullah Babar said.

The panel drafting the chargesheet has made "significant progress" in listing the charges against Musharraf, he said.

Officials said the charges against the president are likely to be filed later in the week amid a rising clamour in the ruling coalition that he step down.

Presidential spokesman Major General Rashid Qureshi said Musharraf will not resign "in any situation" and battle it out.

Musharraf will have the right to defend himself after the impeachment motion is moved.

Ahead of the National Assembly session, Musharraf held talks with his supporters in the opposition Pakistan Muslim League-Q during which he vowed to prove "false before the nation" all charges against him, the local Geo TV reported.

PPP chairman Asif Ali Zardari has alleged that Musharraf "misappropriated" $700 million of aid given by Washington to Islamabad [Images] for supporting the war on terror.

The allegation made by Zardari was also discussed when PML-Q lawmakers --  Marvi Memon, Amir Muqam and Sheikh Waqas Ahmed -- met Musharraf for about an hour in Rawalpindi.

Leaders of the ruling coalition have also accused Musharraf of incompetence and pursuing economic policies that have brought Pakistan to the brink of a economic crisis.

After the four provincial assemblies pass separate resolutions asking Musharraf to seek a vote of confidence, the PPP-led coalition will submit an impeachment motion and chargesheet against Musharraf in the National Assembly.

Babar said the coalition had uncovered evidence of "horrendous" crimes allegedly committed during the beleaguered president's rule. He did not elaborate.

"We are in the government now and have access to many previously confidential documents. After going through these documents, we are surprised over the horrendous nature of the crimes committed by President Musharraf during his almost nine-year rule," he said without commenting on reports that the charges included those of corruption and murder.

While there have been questions as to whether the coalition had the numbers in the two houses -- the National Assembly and the Senate, Zardari said he was "110 per cent sure" of the success of impeachment motion.

Both houses of Parliament have a combined strength of 442, and the motion will have to be passed by a two-thirds majority or 295 members. Anti-Musharraf parties have a total of 274 members 235 in the assembly and 39 in the Senate, which is short of the magic number.

Meanwhile, Musharraf accused the ruling PPP of trying to "impose" its own policy on the nation over the Kashmir issue with India.

"The PPP wants to impose its own policy on the Kashmir issue above Parliament," Musharraf was quoted as saying by the local Geo TV during a meeting with PML-Q lawmakers Marvi Memon, Amir Muqam and Sheikh Waqas Ahmed.

Musharraf, who is facing impeachment, said he had documented evidence in this regard and the nation would know the facts in two to three days.

Referring to his differences with the PPP during the hour-long meeting, Musharraf said he had objected when the party wanted to place its own men in some key positions.

The president also thanked PML-Q for its support in his hour of need.

Born in Delhi [Images] on August 11, 1943, in pre-partition India to a family of civil servants, Musharraf faced the ignominy of becoming the only president in Pakistan's history to be impeached.

The ruling coalition initiated the parliamentary proceedings against Musharraf, incidentally on his birthday.

Ironically, Musharraf had himself summoned the session on Monday at the behest of the government.

The former commando grabbed power in a bloodless military coup in October 1999 toppling the government of Nawaz Sharif, who has now trained guns against him along with his key ally PPP for his ouster.

Unlike last year when he was greeted by a large number of people including ministers and diplomats during the tenure of ally PML-Q, this time the president appeared isolated with the Pakistani media also avoiding any mention of his birthday.