By Hamid Shalizi and Jessica Donati
KABUL (Reuters) - The mammoth task of auditing eight million votes cast in the second round of Afghanistan's presidential election will restart on Saturday, the electoral commission said on Thursday, but disputes still hang over the process.
Allegations of mass fraud have cast doubt over the outcome of the vote that aims to transfer power democratically for the first time in Afghan history before most foreign troops pull out at the end of the year.
A U.S.-brokered agreement to audit all ballots defused a crisis this month, but the process has stalled three times since and the candidates have yet to agree on how to disqualify votes.
The audit stopped last weekend because of technical differences, and the suspension was extended due to the Eid al-Fitr holiday this week.
The United Nations on Thursday asked both candidates, Abdullah Abdullah and Ashraf Ghani, to fully engage in the process, warning against further delays.
"Any delays, any uncertainties, have a major, negative impact on both the political and economic situation in Afghanistan," said Jan Kubis, the top U.N. official in Afghanistan.
"It's high time to complete the process of the elections."
The deal, brokered by U.S. Secretary of State John Kerry, also introduces the idea of a national unity government that would soften the blow for the losing candidate, although the two sides have yet to hammer out an agreement.
Preliminary results from the vote put former finance minister Ghani, a member of Afghanistan's biggest ethnic group, the Pashtuns, in the lead by about a million votes.
Abdullah, a former foreign minister, is part Pashtun but associated more with the ethnic Tajik minority.
Diplomats involved in the audit process say perhaps a quarter of the votes cast could be thrown out, if not more. At the current pace, they say it could take until the end of the year to complete the audit.
(Editing by Jeremy Laurence and Robert Birsel)