By Hamid Shaikh
GARHI KHUDA BAKSH, Pakistan (Reuters) - Supporters of embattled President Asif Ali Zardari gathered at the grave of his wife Benazir Bhutto on the fourth anniversary of her assassination on Tuesday, two days after a rally staged by rivals threatened to upend Pakistan's political order.
Zardari, who became president after the former prime minister was killed in 2007 following her return from self-imposed exile, is facing perhaps the greatest threat to his government.
"Her (Bhutto's) assassination was ... a conspiracy to rob Pakistan of its best hope to establish a fully functional democracy," Zardari said in a statement on Tuesday.
He urged "all the democratic forces and the patriotic Pakistanis to foil all conspiracies against democracy and democratic institutions."
Members of Zardari's Pakistan People's Party say opponents are working with the Supreme Court and the army to bring down the government.
The death anniversary came the same day the Supreme Court began deliberations on whether it could open its own investigation into the so-called "memogate" scandal.
It also came two days after cricketer-turned-politician Imran Khan brought at least 100,000 people into the streets of Karachi in a rally that increases pressure the government and cements his standing as a political force.
The memogate hearing, which was adjourned without any decision, is likely to be front-page news on Wednesday, reflecting the intense interest in incremental developments in the crisis.
CALL FOR INVESTIGATION
It involves the publication an unsigned memo seeking Washington's help to rein in the military after U.S. forces found and killed al Qaeda leader Osama bin Laden in Pakistan in May.
Pakistan's then ambassador to the United States, Husain Haqqani, has been accused of writing the memo on behalf of the government. He denies involvement but has resigned pending an investigation.
Chief of Army Staff General Asfaq Kayani has called for an investigation into the memo, which has set off a flurry of speculation of a rift between the government and the army which has ruled Pakistan for almost half of its 64-year history.
The political crisis also comes as ties between the United States and Pakistan drop to their lowest point in decades following a NATO cross-border attack on Nov 26 that killed 24 Pakistani soldiers. A U.S. report on the incident blamed both sides for poor communications and bad maps.
The incident infuriated Pakistan's army, which is demanding an apology from President Barack Obama, and led to the closure of supply lines for coalition forces fighting in Afghanistan.
The army has denied planning to take power but Prime Minister Yusuf Raza Gilani has added to the intrigue and confusion.
Last week he surprised many by implicitly suggesting the military was a "state within a state" before reversing himself on Monday night and saying he was "happy" with Kayani and would not fire him or the head of the Inter-Services Intelligence agency, as some media reports claimed.
"You have seen that in every era there have been attempts to somehow create rifts between institutions," he told reporters as he stood beside Bhutto's grave. "Every institution should work within its constitutional space. I'm talking about all institutions."
One member of the National Assembly said Gilani was trying to explain that the civilian-military imbalance would not be solved overnight.
"The prime minister tried to make the people realize that the imbalance is still there and there are certain things that are beyond our control," the assembly member told Reuters.
Party members were still upbeat, however, the lawmaker said, and the ruling coalition enjoyed strong support from its partners in parliament. Local supporters echoed that sentiment.
"The army or the Supreme Court can do nothing to the government and our party," said Ali Gohar, 45, a PPP worker from the town of Sukkur who has come to pay homage to Bhutto.
"The PPP has the blood of martyrs in its foundations and we will support it as long as we live."
(Writing by Chris Allbritton; Additional reporting by Qasim Nauman and Faisal Aziz in ISLAMABAD; Editing by Nick Macfie)