KABUL (AFP) - Afghanistan's fraud-hit election teetered on the brink of collapse Wednesday as one of the two candidates boycotted the UN-supervised vote audit set up to end a prolonged dispute over the rightful winner.
Abdullah Abdullah, who claims that massive fraud was committed against him in the June 14 vote, pulled out of the audit after his senior campaign officials dismissed the process for invalidating fake votes as "a joke".
The stand-off between Abdullah and his poll rival Ashraf Ghani has threatened to revive ethnic violence in Afghanistan as US-led NATO troops withdraw after 13 years of fighting Taliban insurgents.
The audit of all eight million votes was halted on Wednesday when Abdullah's observers refused to participate - despite a US-brokered deal in which both sides vowed to support the recount and respect its outcome.
"We will not join the process today, and maybe we will not re-join the process at all," Fazel Aqa Hussain Sancharaki, a spokesman for the Abdullah campaign, told AFP.
"Talks are ongoing with the UN. If that reaches an agreement, we will come back. If not, that is the end of it."
With both candidates claiming victory, outgoing President Hamid Karzai has upped the stakes by insisting that his successor will be inaugurated on Tuesday.
The UN has voiced fears of a return to the ethnic divisions of the 1990s civil war if the election impasse sets off street protests and a spiral of instability.
Any backlash against the final result could split the country, since many of Ghani's supporters are Pashtuns in the south and east, while Abdullah's loyalists are Tajiks and other northern groups.
"I think now they know they have lost the election, and to hide their defeat they are trying to make excuses," Aleem Fedaee, a member of Ghani's team, told reporters.
"We have already agreed on the procedures. Any changes will be against the law and against the agreements."
After Abdullah's team issued its withdrawal threat on Tuesday, the United Nations mission in Afghanistan underlined that both campaign teams were consulted on the audit and have "joint oversight" of the process.
Abdullah, a former anti-Taliban resistance fighter, won the first-round election in April out of a field of eight candidates, but preliminary results from the June run-off showed that he was far behind Ghani.
Some furious supporters of Abdullah have pushed him to form a "parallel government", while officials have denied reports that some ministers planned to set up a "interim administration" to take power.
Western nations that have sent troops and billions of dollars worth of aid to Afghanistan since 2001 still hope that a credible election will be a flagship legacy of progress made since the austere Taliban era.
US-led foreign troop numbers have declined from a peak of 150,000 in 2012 to just 44,300 now, with Afghan soldiers and police struggling to beat back new Taliban offensives in the south and east.
Karzai, who has been president since the Taliban regime was ousted in 2001, has said the uncertainty has badly damaged Afghanistan's fragile security and economy.