By M Ilyas KhanBBC News, IslamabadHe left the country in late 2008 and has since been living in self-imposed exile in London.
With arrest warrants issued against him in at least two murder cases, and given his rather dismal electoral prospects, many ask why he is returning at all?
He has now been granted protective bail for up to two weeks, making his return more certain.

This is seen as his only chance to come back to Pakistan; he wants to vindicate himself, and if he reverses his decision now as he has done a couple of times before, he will have to wait five years before another opportunity presents itself.
Judicial crisis Pakistanis have few fond memories of his rule that stretched from 1999 to 2008.
Pro-democracy groups opposed the coup that brought him to power in 1999.
His subsequent decision to align with Western powers in their "war on terror" also proved to be hugely unpopular.
But the real crisis set in with the March 2007 sacking of Chief Justice Iftikhar Chaudhry, which sparked a country-wide protest movement by lawyers and civil rights groups.
He courted further controversy in July 2007 by ordering a bloody siege of Islamabad's Red Mosque, that led to the killing of more than 100 people, mostly students of a mosque seminary who had been acting as the vigilante "vice squad" against music stores, massage parlours and prostitution dens in the federal capital.
While many supported action against the Red Mosque brigade, the ensuing bloodshed provided a rallying point for right-wing religious groups and caused militant factions in the north-west to come together in a violent anti-Islamabad alliance called the Tehrik-e-Taliban Pakistan (TTP) - the Pakistani Taliban.
In December that year, one of Pakistan's most popular politicians, Benazir Bhutto, was assassinated, allegedly by TTP.
A 2010 United Nations inquiry into the murder accused Gen Musharraf's government of "wilful failure" to protect the former prime minister.
He resigned as president in August 2008 to avoid impeachment by a new, democratically elected parliament.
Dangerous path While some political forces, like the PML-N which he had toppled from power in 1999, wanted his head, the government led by President Zardari's PPP party allowed him a safe exit from the country.
He is now retracing a path that is fraught with dangers.
He is wanted in the murder trials of Benazir Bhutto and a Baloch tribal leader, Nawab Akbar Bugti.
He is also on a court notice to appear before a judicial inquiry instituted by the Supreme Court to investigate the Red Mosque siege.
Besides, there are suggestions he could be hauled in on a high treason charge for sacking the entire higher judiciary in November 2007.
And he is a prime target for Taliban militants, who have considerable presence in Karachi, the city where he is expected to land on Sunday.
According to informed circles, he has been "war-gaming" various scenarios of his arrival in Pakistan with his lawyers, political aides and former colleagues in the army.
He is also understood to have been talking to the ruling circles of Saudi Arabia, which has often arbitrated political disputes in Pakistan. He visited that country just two days before his scheduled departure for Pakistan.
His minimum target appears to be to avoid arrest, and win a seat to the parliament.
And his supporters are also banking on the assumption that the army, which has an overtly political image in Pakistan, will not let a former chief to be dragged in the courts and humiliated.
Last year, both the government and the Supreme Court avoided any tangible action against a former army chief and a former head of the ISI intelligence service after allegations of rigging the 1990 elections were proved against them.
As for winning a parliament seat, he appears to be banking on some scattered support he garnered during his rule.
No runawayProminent among his supporters is a segment of young business entrepreneurs and professionals in the main urban centres such as Karachi, who benefited from a vibrant spell in consumer economy under his rule.
A political rally in Karachi which he addressed via a video-link from Dubai in January 2012 did draw a respectable crowd.
Analysts believe that with some help from a potential political ally, such as the MQM, he can translate this support into a parliamentary seat. It is also thought that he has been working on political alliances elsewhere.
But there are several unknowns in this equation.
The MQM may or may not have agreed to an election arrangement with him. Likewise, the army or the Saudis may or may not want to prevail on the Pakistani authorities to let him run a smooth election campaign.
Whatever his fate, Gen Musharraf can be sure of one thing; once he has set foot in Pakistan, he will not go down in history as a runaway or a quitter.

bbc.com