Egypt's secular opposition is claiming fraud in a referendum that the ruling Islamists say approved a new constitution.
On December 23, the opposition National Salvation Front said it will appeal the results of the two-stage referendum because "fraud and violations" skewed the results.
The second leg of the referendum took place on December 22.
Front member Amr Hamzawy told journalists that they are "asking the [election] commission to investigate the irregularities before announcing official results."
Germany became the first Western nation to back the call for an investigation into the results.
Foreign Minister Guido Westerwelle said that the new constitution "can only meet with acceptance if the process of its adoption is beyond reproach."
Egyptian state news agency Al-Ahram is already reporting a "resounding victory," citing preliminary results that the new charter was approved by 64 percent of voters.
Earlier, Egypt's ruling Muslim Brotherhood party released preliminary results that show 64 percent of voters have approved the new constitution.
The Muslim Brotherhood also posted information on its website that showed more than 70 percent of voters in the December 22 second round said "yes" to the new constitution.
Turnout for the referndum was 32 percent among Egypt's 51 million eligible voters.
The country's election committee is expected to confirm the final result on December 24.
Based on reporting by Reuters and AP