At the general assembly of his al-Ghad party on Tuesday, Nour shrugged off a leadership challenge within his party and a court date next week in his trial on forgery charges. His followers have said both were concocted by the ruling party to damage him.
He warned the government, in a defiant tone, against framing him or freezing his party.
"I am warning the regime. If the desire of the (ruling) National party is to take revenge on al-Ghad by pushing it into hell, we are ready for it. Our reaction will be very violent and swift," he said to loud applause.
The 40-year-old Nour finished far behind President Hosni Mubarak in the 7 September election - with about 7% compared to 88% for the incumbent. Still, his second place result was a surprise since a more established opposition figure, Noaman Gomaa of the Wafd Party, had been considered the more likely runner-up.
However, the Wafd and other parties in the notoriously weak and fragmented opposition have so far shown little enthusiasm for lining up behind Nour in the parliamentary elections that begin on 8 November.
"Today the al-Ghad party is leading the opposition," Nour told the party conference in a two-hour speech. "Take a vow from us, we will not betray the Egyptian street. We are not going to let go of our principles and we won't sell out."
Nour has reached out to the
He suggested he would work with non-official opposition movements like the pro-reform group Kifaya rather than the established political parties.
"We will coordinate with Kifaya and other forces in the parliament elections against the National Democratic Party," he said.
In the presidential campaign, Nour also approached the Muslim Brotherhood, the fundamentalist movement that is banned but is believed to be Egypt's most powerful opposition group.
Nour offered to resign in his speech, but the conference voted overwhelmingly for him to remain in his position as party leader.
On Sunday, Nour returns to court in his trial on charges that he ordered the forging of signatures in his party's registration last year.
Earlier this year, he was arrested on the charges and his detention raised complaints from the United States, Egypt's closest ally, which has been pressing Mubarak to allow democratic reforms.
Nour says the government is trying to frame him, and during a previous court session one of the top prosecution witnesses proclaimed that security forces had threatened his family to force him to testify against the politician.
If found guilty, Nour who currently has a seat in parliament would be prevented from running in the upcoming election.