CAIRO - Egypt's already bumpy political transition could be stopped in its tracks on Thursday when a court considers a law that could disqualify one of two run-off candidates in this weekend's presidential election.
The Supreme Constitutional Court is expected to decide on the validity of the law passed by the Islamist-led parliament that sought to bar Ahmed Shafik, Hosni Mubarak's last prime minister, from the vote pitting him against the Muslim Brotherhood's Mohamed Morsy.
The court will also review the legality of rules that governed a parliamentary election earlier this year in which Islamists swept up seats.
A judicial body has already recommended that both laws be overturned, allowing Shafik to continue his bid and possibly dissolving the parliament. The court is not bound to follow that advice, but it is a likely indication of the ruling.
Yet the legal drama that has left Egyptians on tenterhooks two days before the Saturday and Sunday run-off is emblematic of the tortuous and messy transition overseen by the council of army generals since Mubarak was ousted 16 months ago.
"This sort of overhang is a reflection of our current state of affairs. Only days before the election and there is legal uncertainty," Judge Mohamed Hamad al-Gamal, a former head of the state council, told Reuters.
Seeking to derail presidential bids by senior Mubarak-era officials, parliament approved the law on April 12 to strip political rights from anyone who served in top government or ruling party posts in the last decade of Mubarak's rule.
That law initially prompted the election committee to disqualify Shafik. But he was let back into the race on appeal and pending the constitutional court ruling.
In a security message its website, the U.S. embassy in Cairo said any decisions from the Thursday's court session may lead to protests. "These court decisions may further raise the level of tension as Egypt heads to the polls to elect their first democratically elected president," it said.
Legal experts say they expect Shafik will be allowed to run. The court could avoid a verdict saying the election committee was not the competent authority to refer the case, but the experts thought that unlikely.
"We will request that the court issues its ruling tomorrow to end this controversy and allow Egypt a sense of political stability," Shafik's lawyer Shawky el-Sayyed told Reuters. "All the indicators suggest that the election will continue on time."
Lawyer Bahaa Abou Shoka said the law was unconstitutional for seeking to bar a citizen - or enforce some form of punishment - without proof of a crime. "This condition is lacking in the law," the lawyer said.
On parliament, an administrative court said in February that the election rules were unconstitutional. In that vote, two-thirds of seats were allocated to parties and the rest to individuals who were supposed to be independent of any party.
The administrative court judge said political parties should not have been allowed to run for the individual seats, although they did. He also said half rather than a third of the seats should have been apportioned to individuals.
"If it is proven that the election rules were flawed or unconstitutional, then the entire election process is void," Judge Gamal said. "It would mean that this parliament is unconstitutional, illegitimate and must be dissolved."
Some judicial sources say the constitutional court could delay a ruling on parliament until after the presidential vote.
Under Mubarak, the Supreme Constitutional Court used similar arguments to rule election laws illegal in 1987 and 1990, forcing the dissolution of parliament, overhauls of the electoral system and early elections.