Hazem Salah Abu Ismail

TEL AVIV - An ultra-conservative Islamist running for president in Egypt is facing accusations that his mother was an American citizen, a charge that if true, could see him disqualified from the race.

Hazem Salah Abu Ismail, a lawyer who became a prominent and fiery preacher on TV, is a frontrunner in the race to replace Hosni Mubarak, deposed last February following an 18-day uprising. He is a Salafist, a sect of Muslim fundamentalists known for their long beards and strict interpretation of Islam.

Abu Ismail denies the allegations that his mother held a U.S. passport before her death, saying it's an attempt to tarnish his candidacy. Candidates whose parents are not Egyptian or are dual nationals are barred from running.

"I have not seen worse days. There is a conspiracy against me by the Salafis who refuse to support me and their supporters," Abu Ismail told Al Arabiya television channel. "What you hear in the media is one thing and what happens behind closed doors is something else."

Abu Ismail filed a suit against the head of the Supreme Electoral Commission and the Interior Minister on Wednesday to prove that his mother only had Egyptian citizenship, according to Egyptian newspaper Al Ahram.

Abu Isramil said that reports pointing to California voter registration records as proof of his mother's American citizenship are wrong, that the name listed for her husband is incorrect and that voter registration does not automatically make one a citizen. Abu Ismail said his mother did have a Social Security number as well as a green card in order to be near his sister, who lives in the U.S. and holds a American passport.

Abu Ismail submitted the necessary documents for the election amid much fanfare last Friday, including a reported 150,000 signatures when just 30,000 are required.

"I am not that impulsive to risk my reputation in the society that trusts and supported my platform," Abu Ismail told Al Arabiya. "It was my increasing popularity that led some people to try to destroy me."

"If presidential elections are not fair or their results are manipulated, I will go to international courts if the Egyptian judiciary will not do me justice," he said. "The era of subjugation is over."

The first round of the elections are to be held next month, with a runoff, if needed, in June. After that, the military council that has been ruling Egypt since Mubarak was deposed has vowed to go back to its barracks.

The liberals who ignited last January's revolution have become a distinct minority on the political stage, with Islamists dominating more than 70 percent of parliament. In a surprise move, the Muslim Brotherhood's Freedom and Justice Party, which holds the most seats in parliament, decided last weekend to run a candidate in the presidential election. That candidate, millionaire businessman Khariat al-Shater, immediately shot to the top of the field.

In the few days since he became a candidate Shater has been trying to get the Islamist base to coalesce around his candidacy. On Wednesday, Reuters reported that he told a religious group that "Sharia [law] was and will always be my first and final project and objective."

But Abu Ismail is not going down without a fight, saying in a statement on his Facebook page that news of him dropping out is false and that electoral authorities have not made their ruling.

According to Al Ahram, the Salafist Front has announced that on Friday it will hold a march from Cairo Al-Fateh mosque to Tahrir square to protest the allegations.