* Prolonged vote audit impacting security, economy
* Candidates still far apart on political framework
By Jessica Donati
KABUL, Aug 25 (Reuters) - Afghanistan's next president was meant to be inaugurated on Monday but the deadline has been pushed back to Sept. 2 as rival candidates remain deadlocked over who won an election meant to mark the troubled country's first democratic transfer of power.
Rivals Abdullah Abdullah and Ashraf Ghani, as part of a U.S.-brokered deal, must form a government of national unity and cooperate on an audit of all eight million votes that were cast to eliminate concerns over widespread electoral fraud.
The inauguration had to be pushed back a second time since a June run-off vote because officials from both camps, along with the electoral body, doubted the target would be met.
The new inauguration target of Sept. 2, if it is met, would allow the next president to take power before a key NATO summit in Wales starts two days later. The summit will determine how much aid Afghanistan will get after most foreign troops pull out at the end of the year.
"The Independent Election Commission (IEC) is trying very hard to finish the process as soon as possible," said the commission's spokesman, Noor Mohammad Noor.
The bitter stand-off has dashed hopes for a smooth transition of power from President Hamid Karzai, who has run Afghanistan since U.S.-backed Afghan forces toppled the Taliban in 2001. He is barred by the constitution from running again.
Noor said 70 percent of votes have been inspected so far, a month into the U.N.-supervised audit, but the most contentious ballots have yet to be scrutinised.
"Prolonging of the presidential process has affected people's daily life, particularly in security, economy and governance," Karzai's office said on Sunday after a meeting with the candidates to urge them to cooperate.
"This must end as soon as possible."
Results from the June 14 run-off put Ghani, a former World Bank official, in the lead. Abdullah rejected the result, accusing his rival's team of rigging the election with Karzai's help. Ghani and Karzai have denied the charge.
The IEC was due to start invalidating votes later on Monday, a process that will determine how many votes are thrown out based on findings submitted by hundreds of auditors.
A commission appointed by members of both camps has been meeting for days to work out a political solution but they have made little progress so far.
"They tried to narrow the differences down and find some common ground ... but they could not agree," said Abdullah's spokesman, Mujib Rahman Rahimi.
"The two camps are representing two different philosophies."
Rahimi could not say for sure whether the new deadline for inaugurating the next president would be met.
"Honestly, I cannot come out with something definite on that, but I hope. It's Afghanistan. Things are unpredictable."
Ghani's team declined official comment. One of his campaign officials, speaking on condition of anonymity, said little progress had been made interpreting the framework for a power-sharing deal.
"Nothing yet has added to the political framework and the commission couldn't reach an agreement in most of the areas (discussed)," the official said, adding that the candidates were meeting to try to break the deadlock. (Additional reporting by Hamid Shalizi and Krista Mahr; Editing by Maria Golovnina and Paul Tait)