THE struggle to certify the results of Guatemala's first-round presidential election suffered another setback on Saturday after the chief justice of the supreme court issued an order blocking the certification.

Chief Justice Silvia Valdes Quezada issued the unusual order late on Friday. She ruled the process could not go forward until the electoral authorities, who conducted a review of precinct vote tally sheets from the June 25 election, reported back to her on their methods and any inconsistencies found.

Ms Valdes Quezada said they had to do that within 12 hours.

The reviews found improperly marked or counted votes amounted to less than 1 per cent of the total, not enough to change the results.

The electoral observers’ mission from the Organisation of American States said in a statement on Saturday that it was concerned by “the attempt to continue judicialising the electoral process.”

The group said the tally sheet review “was done in a satisfactory manner, complying with the principles of maximum transparency and public access.”

The Supreme Electoral Tribunal said in a statement on Friday that the review “confirms the preliminary results published on June 25,” and urged political parties “to accept with maturity the election results, which represent the legitimate will of the people.”

Edie Cux, director of Accion Ciudadana, the local chapter of nongovernmental organisation Transparency International, said: “The result has not changed, the period for the review has practically closed and as established by the law they must now certify the results.”

Neither Bernardo Arevalo nor Sandra Torres got 50 per cent of the vote, so they would be scheduled to face each other in a run-off vote on August 20.

It was a surprise to many observers that Mr Arevalo, of the centre-left Seed Movement party, polled as well as he did. Ms Torres, the candidate for the conservative UNE party, is making her third bid for the presidency.