The Muslim Brotherhood established the Freedom and Justice Party and supplied its leaders.
Essam El-Aryan, the party vice chairman, told the BBC that 40% of its members are from the Muslim Brotherhood.
The party got legal status on 6 June 2011 and is headed by Mohamed Morsi.
It is an Islamist party that wants to establish an Islamic state.
Programme and goals
It aims at achieving freedoms and justice, especially social justice.
It calls for establishing an Islamic economic system, where there is no interest rate.
It affirms a full democratic regime based on Shura.
It also states that Islamic Sharia principles are the main source of legislation and all freedoms are to be within the limits of Sharia.
"Freedoms must comply with the Islamic Sharia," Essam El-Aryan told the BBC.
Mr el-Aryan says parliament is responsible for making sure that all laws comply with Sharia law. But there is still some doubt about what interpretation of Sharia the party might use if it won power.
The party is the leader of the Democratic Alliance.
Mr el-Aryan told the BBC that the party is the strongest in the alliance, with experienced members who have already served in previous parliaments.
The alliance has candidates in all party list districts and in more than 90% of individual lists districts.
Several parties left the alliance because they thought that the Freedom and Justice party controlled the parties' lists and use of religious slogans.
The party is one of few that have enough money to put forward large numbers of candidates in the elections and make TV advertisements during the campaign.
It also held many electoral conferences and marches.
The party relies on members' subscription and donations from rich members.
Mr el-Aryan says the party counts on personal communication between party leaders and candidates, and ordinary people.
Women and Copts
The party nominated 46 women on its lists, which Mr el-Aryan said was in line with a legal requirement to put one woman in each list.
The Freedom and Justice Party calls for equality between women and men, but says women must strike a balance between their family duties and public life. This means some constraints on women's role in society in general, and in politics in particular.
There are no Copts on Freedom and Justice Party lists though there are two in the Democratic Alliance. Mr el-Aryan said they had chosen the alliance because of their political position and not because they are Copts.
Mr el-Aryan said the Freedom and Justice Party tried to attract them, but those efforts failed.
Constitutional principles document (El-Silmi)
The party rejected the document as unconstitutional and not reflecting the people's will, calling for a demonstration on 18 November over the issue.
"The army wants to be a state inside a state" Mr el-Aryan told the BBC.
The Freedom and Justice Party rejects appointing members of the constitutional committee that will draft the new constitution, and the idea that the army could protect constitutional legitimacy, as in the Turkish model.
Chances in parliament
Mr el-Aryan said the party's membership stands at about 120,000 and that it nominated the majority of the Democratic Alliance's candidates.
The party is supported by the Muslim Brotherhood, which has an extensive presence, as well as financial and human resources, in several regions in Egypt.
Some experts expect Islamists to win 35% of seats, and that 25% of those will be for the Freedom and Justice party.
Mr el-Aryan thinks that the Democratic Alliance will get 40-45% of seats.