Cairo, Egypt (CNN) -- The scene Friday in Cairo's Tahrir Square felt familiar. Only this time, the protest came ahead of critical elections.
Thousands of Egyptians from across the political spectrum turned out at the iconic plaza unified in their opposition to remnants of Hosni Mubarak's regime and in their determination to protect the goals of a hard-fought revolution.
Rival factions put their differences aside to come together against military rule. The Muslim Brotherhood joined hands with liberals to voice discontent with an electoral process that has disqualified several candidates, including the leader of the Islamist group.
The Supreme Presidential Electoral Commission said this week that it endorsed a previous decision to exclude 10 of 23 candidates from voting scheduled for May 23 and 24 due to "legal irregularities."
Among the barred candidates is the Muslim Brotherhood's Khairat el-Shater.
Alaa Ayad, a campaign spokesman for el-Shater, called the disqualification a "political decision" and said the party's lawyer will appeal it.
"This decision may cause tension on the streets," Ayad said.
Ultra-conservative Hazem Abu Ismael was banned due to information that his mother holds a U.S. passport, which is against the rules of candidacy.
A representative for Ismael issued a similar warning to Ayad's, saying the candidate's "followers are angry and will take to the streets until he is allowed to run."
"We are convinced that Abu Ismael is targeted and that there are external and internal conspiracies against him," lawyer Nizar Ghorab said.
But also barred was the controversial Omar Suleiman, Mubarak's former spy chief, who entered the race in the eleventh hour and failed to gather enough signatures required to be on the ballot.
His disqualification suggested the panel, which includes members connected to the Mubarak regime, was not politically motivated but had based its decisions solely on the law.
Some saw Suleiman's candidacy as a move that could galvanize rival political parties to unite in preventing a return of any vestiges of the former regime.
Next month's polling will be the nation's first presidential election since Mubarak's ouster in February 2011.The Muslim Brotherhood's political wing won nearly half the seats in the first parliamentary elections in November.
Egypt's military has been in control since Mubarak fell, but it has pledged to yield power to a civilian government. However, many Egyptians have grown increasingly concerned the generals will try to cling to power and remain in charge of the country's executive and judicial branches.
Adding to the tension is an effort to craft a new constitution and a verdict in Mubarak's murder trial, scheduled for June 2.
Journalist Ian Lee contributed to this report.