Abdullah Abdullah, president Hamid Karzai's rival in the second round of Afghan­istan's presidential election, is reportedly close to quitting the poll.

Abdullah called for the resignation of key election officials, cabinet ministers and provincial governors as a way to mitigate fraud and corruption. The deadline for those conditions to be met expired last night.

A senior adviser said that in talks on Friday, Abdullah's team decided he should not take part in the poll.

In a meeting with Karzai earlier this week, Abdullah's demands for resignations were turned down. But this election has been a protracted and murky affair and, until an official announcement is made, the details of any final decision on whether he is standing won't be known.

Hundreds of thousands of votes were discounted from August's first round of voting.

The UN-backed Electoral Complaints Commission's (ECC) action meant Karzai's total was reduced to below the 50% plus one vote threshold for outright victory, indicating a run-off poll was needed.

Among the "minimum conditions" Abdullah has set for holding a relatively fair and free contest to be accepted, is the sacking of the head of the country's Independent Election Commission (IEC), Azizullah Lodin.

On Monday, Adbullah said Lodin had "no credibility". Lodin denies allegations he favoured Karzai. One of Abdullah's senior advisers, Ahmed Wali Massoud, said he was unhappy nothing had been done to redress the electoral system's problems.

"The fact is the infrastructure of this fraud is still there. Almost 1.5 million votes were rigged. Nothing has changed," he told reporters. "So if you go back and do the second round election, it means it will happen again. So, therefore, I don't think we would be willing to participate."

Earlier, the IEC announced it planned to open 6,322 polling stations for the run-off – more than it did during the first round. The ECC had recommended cutting the number from 6,000 to about 5,800 to ensure there would be enough monitors to limit fraud and troops for security.

Abdullah served as foreign minister in the shortlived government headed by the North­ern Alliance and continued as "foreign minister in exile" throughout the rule of the Taliban, which was ousted in 2001. He continued in that role under the Karzai government, leaving in 2006.

Former US president George Bush warned last week that "the world would face serious threats" if the resurgent Taliban and al-Qaida are allowed to retake control of Afghanistan.

Bush spoke out during a visit to Delhi, India as president Barack Obama decides whether to commit tens of thousands more troops to Afghanistan.

Bush said a peaceful, democratic Afghanistan is vital to the region. "If the Taliban and al-Qaida and their extremist allies were allowed to take over again, they would have a safe haven, and the Afghan people, particularly the Afghan women, would face a return to a brutal tyranny," he said.