The court that sentenced a top opposition leader to five years in prison last month - in a trial that strained US relations - issued a report on Saturday that explained that Ayman Nour was convicted because of the "danger" posed by the defendants' sophisticated forgery techniques.
Nour's lawyers responded that they would register an appeal within a month, as provided under Egyptian law.
Nour, 41, who was a distant runner-up to President Hosni Mubarak in last year's presidential elections, was convicted Dec. 24 of forgery, a charge he has said the government invented to eliminate him from politics.
Six co-defendants who allegedly assisted Nour in the fraud and testified against him were also found guilty in the trial, which was criticized by the United States and also raised doubts about Mubarak's sincerity in bringing greater democracy to Egypt.
Nour pleaded innocent to ordering the forging of signatures to register his opposition Al-Ghad party in 2004.
In its 80-page report, the court said Nour's denials of the charges were obvious attempts "to escape questioning about the crimes he had committed."
Amir Salem, Nour's chief lawyer, told The Associated Press Saturday that he would ask for suspension of the verdict until the appeal was decided.