Presidential candidate Abdullah Abdullah demanded Wednesday that Afghan electoral authorities stop counting ballots from a weekend runoff vote, citing new allegations of widespread fraud. The election commission refused and appealed to all sides to await final results.

The discord set the stage for a showdown that could threaten Afghanistan’s first peaceful transfer of authority.

Abdullah, a onetime aide to a famed warlord during the Afghan anti-Soviet guerrilla campaign, said monitors deployed by his campaign to the polls had recorded massive ballot box stuffing and other irregularities. He also announced his team was suspending relations with the Independent Election Commission, accusing it of interfering in the vote and inflating turnout figures.

The finger-pointing in the June 14 election pitting Abdullah against Ashraf Ghani Ahmadzai mars what Western officials had hoped would be an important step toward democracy for the troubled country as the U.S. and its allies wind down their 13-year combat mission. Both candidates have promised to sign a security pact with the United States that would allow nearly 10,000 American troops to stay in the country beyond the end of this year to train Afghan security forces and perform counterterrorism operations.

President Hamid Karzai, the only leader the country has known since the 2001 U.S.-led invasion that ousted the Taliban, was constitutionally barred from seeking a third term.

Abdullah’s team has said its exit polling shows Ahmadzai with a 1 million-vote lead in the current round and claimed election workers and government officials had engineered fraud to help him.

“We announce that we have no confidence or trust in the election bodies,” Abdullah said at a news conference. “The counting process should stop immediately and if that continues, it will have no legitimacy.”

He proposed that the two candidates form a joint committee under U.N. supervision to resolve the issue.

A spokesman for the electoral commission, Noor Mohammad Noor, said the vote count was continuing with national and international observers monitoring the process. Preliminary results are not due until July 2, followed by final results on July 22, according to the official timetable. Electoral officials have said they would release partial results before that.

“The process will not be stopped. This is Independent Election Commission’s decision,” Noor said. “We have a code of conduct for both candidates. We hope they both will obey that code.”

The first round of voting on April 5 went relatively smooth as six other candidates were eliminated and Abdullah and Ahmadzai emerged as the top vote-getters. But the campaign tone for the second round has been sharply more accusatory with the field narrowed to just two hopefuls.

The Obama administration is watching carefully, eager to show progress in the country and get a security agreement signed after announcing it would leave 9,800 U.S. troops in Afghanistan at the end of this year to continue training the Afghans and conduct counterterrorism missions. That number would be cut in half by the end of 2015, and most of the remainder would leave by the end of 2016.