Pakistani President Pervez Musharraf's allies on Tuesday faced a crushing defeat in parliamentary elections that placed the key US ally's political survival in doubt, according to early unofficial results and analysts.
Opposition supporters took to the streets chanting the names of former prime ministers Nawaz Sharif and the slain Benazir Bhutto early Tuesday as early counting showed their parties sweeping the board.
The polls were the final step on the nuclear-armed nation's path to civilian democracy after eight years of turbulent military rule by the increasingly unpopular Musharraf.
"The voters have delivered their verdict, and as democrats we accept their verdict," said Tariq Azeem, a spokesman for the Pakistan Muslim League-Q (PML-Q), which backed Musharraf throughout the last parliament.
Early results appeared to dispel opposition fears that the polls would be massively rigged.
Results showed a "big gain" for Sharif and Bhutto's parties, Azeem told AFP, adding: "If the results are confirmed we will play the part of the opposition as effectively as we can."
High-profile victims who lost their seats included party president Chaudhry Shujaat Hussain and almost all of Musharraf's former cabinet, including close presidential ally Sheikh Rashid.
"The results are shocking," a party official said on condition of anonymity.
State television said that with 158 out of 272 constituencies counted, Sharif's faction of the Pakistan Muslim League had 57 seats, the PPP had 54 and the PML-Q had 21, with smaller parties and independents taking the rest.
Full details are not expected until late Tuesday or early Wednesday.
Musharraf will become a powerless leader at best -- and could lose his job -- if the trends were confirmed, analysts said.
After casting his ballot, Musharraf said he would accept the outcome.
"The result will be the voice of the nation and whosoever wins we should accept it -- that includes myself," he told state television.
Turnout was estimated at more than 40 percent of Pakistan's 81 million eligible voters, election commission secretary Kanwar Dilshad said, indicating similar turnout to previous elections in 1997 and 2002.
Musharraf toppled Sharif in a coup in 1999 but stepped down as army chief in November last year amid political turmoil and bloodshed sparked by his efforts to maintain power.
An influential US senator who observed polling said Pakistan's elections would be viewed as completely flawed if the PML-Q were declared victorious.
"If Musharraf's party beats all odds and ends up being the winner here, I think it will be viewed as a totally discredited undertaking," Senator Joseph Biden told the American television network CNN.
Neither Sharif nor Bhutto's widower Asif Ali Zardari made any initial comments on the results. Spokesmen for both parties said they expected to win the vote and would hold talks with other opposition groups.
Analysts said Musharraf would likely try to woo Bhutto's party and split it from Sharif's, but said the president faced major problems.
"For him the most crucial issue will be his political survival rather than fighting the war against terrorism," said political analyst Hasan Askari, in a warning to Musharraf's Western allies.
Musharraf, the most recent in a series of generals who have ruled Pakistan in its 60-year history, was viewed by the United States as its key ally in the fight against Al Qaeda and Taliban militants based in Pakistan's tribal areas on the border with Afghanistan.
Early results also showed Pakistan's main alliance of Islamist parties faced heavy losses five years after they seized political control in the key North West Frontier Province bordering Afghanistan.
The Muttahida Majlis-e-Amal alliance was the third-largest grouping in the previous parliament with 50 seats but had won just two seats out of 158 in the results announced by state run television.
Monday's polls were overshadowed by a wave of suicide attacks in the preceding weeks, including the blast which killed Bhutto, but election day went ahead without the suicide attacks that many had feared.
In sporadic political violence Sunday and Monday at least 19 people were killed, including two members of Sharif's party. (AFP)
Musharraf allies face defeat in Pakistan vote