Lawyers are to appeal on Friday against an arrest order for Pakistan's ex-military ruler Pervez Musharraf that has thrown the country into flux just weeks before historic elections.

The order from the Islamabad High Court was the latest humiliating blow to the retired general, making a mockery of his promises to "save" the troubled country and contest the May 11 vote after ending four years in self-imposed exile.

It was issued Thursday for the sacking of judges in 2007 when Musharraf imposed emergency rule, one of three cases dating back to his 1999-2008 time in office and for which he has repeatedly been granted bail since his homecoming on March 24.

He is also accused of conspiracy to murder opposition leader Benazir Bhutto in 2007 and over the death of a rebel leader during a military operation in 2006.

But so far no attempt has been made to detain Musharraf.

The 69-year-old retired general sped off with his bodyguards after the order for his plush but heavily fortified home on the edge of Islamabad, where he has remained holed up with riot police carrying shields and batons massed outside.

It is the first time that the judiciary has ordered the arrest of a former army chief of staff. Nuclear-armed Pakistan has been ruled for around half its existence by the army, considered the most powerful institution in the country.

"We will go to the Supreme Court tomorrow (Friday)," said a spokesman for his All Pakistan Muslim League (APML) party, considered unlikely to win any seats after Musharraf was on Tuesday disqualified from running for parliament.

It remains unclear what will happen in the Supreme Court, which is hearing a separate petition demanding that Musharraf face trial for treason for imposing emergency law in 2007, punishable by death or life in prison.

"If he is placed under house arrest and his home is declared a sub-jail we will apply for bail and if not then we will try to get bail before arrest," added APML spokesman Muhammad Amjad.

"He will offer his arrest if it is considered necessary... We have not fled the city," he said.

The Islamabad High Court has separately summoned the capital's police chief to explain on Friday why Musharraf has not been arrested.

Judge Shaukat Aziz Siddiqui said Musharraf had "spread fear in the society, insecurity amongst the judicial officers, alarm in the lawyers community and terror throughout Pakistan".

He said sacking judges was "an act of terrorism", which is punishable by life in imprisonment, and recommended that it be added to the charges against him.

Musharraf seized power in a bloodless coup, which was widely welcomed at the time in Pakistan, but he was forced out and threatened with impeachment in 2008.

The elected prime minister he ousted, Nawaz Sharif, is now the front-runner in the campaign for the May 11 general election.

Sharif told Pakistan's largest private TV network, Geo, late on Wednesday that Musharraf should present himself before the courts for "accountability".