KABUL: Presidential candidate Abdullah Abdullah demanded on Monday the firing of Afghanistan's Independent Election Commission (IEC) chief and suspension of three cabinet ministers ahead of a run-off poll.

Abdullah called for the "immediate dismissal" of Azizullah Ludin and his replacement with another member of the IEC, which critics slammed as biased in favour of President Hamid Karzai during fraud-tainted August elections.

While Abdullah would not spell out the consequences if Ludin and the ministers stayed in place, both a close associate and also a leading analyst predicted he might be paving the way to pull out of the November 7 run-off.

"He has left no credibility for the institution," Abdullah told reporters in his strongest attack so far on the IEC's controversial chairman.

"What's the solution? Another commissioner from the same commission should take his position," the former foreign minister said.

The IEC is a nominally independent body but its members were appointed by Karzai. Ludin is a former presidential adviser.

Abdullah has repeatedly called for a shake-up of the IEC after a separate UN-backed commission rejected around a quarter of the votes from the August 20 first round because of fraud.

Ludin's position was contentious even before the first round, with leading US rights group Human Rights Watch warning that the IEC's institutional pro-Karzai bias meant "that the playing field for all candidates is not level".

In the wake of the fraud revelations, UN chief Ban Ki-moon said that around 200 IEC field officers would be replaced for the second round.

Abdullah also called for the suspension of cabinet ministers whom he accused of breaching rules of impartiality by stumping for votes for Karzai, identifying the interior, education and tribal affairs ministers.

So-called ghost polling stations -- where security was so fragile they did not open but nevertheless returned huge numbers of ballots -- should not open this time round, he added.

There was no immediate reaction from the Karzai camp but the IEC released a statement from Ludin rebuffing Abdullah's calls, saying that the commission was "committed" to conducting the run-off "in an impartial and fair manner".

"The IEC and its authorities are assigned and appointed based on the electoral law. The electoral law gives the president the right to appoint the head of IEC," Ludin said.

"I don't think it is the right of every candidate to ask to be able to appoint and dismiss IEC officials," he said, adding: "I don't think this is a legal request."

Abdullah had said his demands were the "minimum" needed for a fair second round.

"With the implementation of these conditions, we have a chance for the people of Afghanistan... to exercise their will in a better environment."

Ahmad Behzad, a pro-Abdullah lawmaker who campaigned for him in the first round, said the candidate was paving the way to pull out of the contest if he felt it remained tilted in Karzai's favour.

"If these conditions are not met, it means that Karzai once again wants to organise a fraudulent election and I think going to such an election is not wise," Behzad said.

"If the conditions are not met, there is a big possibility of a boycott by Dr Abdullah."

Nasrullah Stanikzai, a political analyst at Kabul University, said Abdullah may be trying to take Karzai's attention away from campaigning, but said it was more likely he was opening the way up for a face-saving pull-out.

"The second and more stronger possibility could be that he knows he will be the loser in the second round and by attaching such conditions, he wants to justify his defeat and is trying to find an escape route," said the analyst.

Stanikzai played down the prospects of Abdullah's demands being met because the law stated that he cannot interfere in government appointments.

Although Abdullah did manage to force Karzai into a second round, the incumbent only fell short of an absolute majority by a third of a percentage point and few observers give his challenger much hope of victory in the runoff.