CAIRO — Egypt's leading democracy advocate, Mohamed ElBaradei, defended his alliance with the country's largest but banned Islamist opposition group, the Muslim Brotherhood, in an interview broadcast Friday — saying that their ideological differences don't preclude sharing goals.The 2005 Nobel Peace Prize laureate has been at the helm of a burgeoning opposition movement in Egypt, calling for legal and constitutional reforms to allow for free and fair elections and put an end the nearly six-decade old military-backed regime in Egypt.RELATED:Egyptian opposition split over upcoming electionsBackground: Fighting the new plague in the land of EgyptEgyptian police crack down on anti-Mubarak protestPresident Hosni Mubarak has ruled for the last 29 years.ElBaradei's call for reform earlier this year attracted a wide range of groups, including Egypt's largest opposition group, the Muslim Brotherhood. The group supported ElBaradei's efforts and collected nearly 90 percent of almost 1 million signatures on a petition calling for reform.However, critics have said an alliance with the Islamist group may cost ElBaradei his liberal-leaning supporters."I am in tune with every Egyptian who believes Egypt needs political and economic reform," ElBaradei said in the interview with the pan-Arab Al-Jazeera satellite television. "The Brotherhood and I were honest with one another that we have total ideological and intellectual disagreement but we agree that we are part of this people and we want a democratic Egypt." He said the group is not seeking to establish a religious state.ElBaradei, the former chief of the UN nuclear agency, returned to Egypt in February to a hero's welcome.ElBaradei said he will pursue his calls for reform through peaceful means, and may even call for civil disobedience.Apart from his petition for reform, he has urged a boycott of the November parliamentary elections, saying they will be rigged. ElBaradei told Al-Jazeera that taking part in the elections will be supporting a "phony democracy."The Brotherhood and other opposition parties will take part in the elections.The 82-year-old Islamist group is the largest opposition bloc in parliament, with a fifth of the seats. Banned since 1954, it has been tolerated to various degrees by the government, and fields independent candidates in elections.ElBaradei said Mubarak's military-backed regime is on the verge of collapse because of rising dissatisfaction, repression and poverty. He said his calls for reform aim to prevent a "revolution of the poor."In the interview, ElBaradei said he hopes for a transitional period to allow for the writing of a new constitution, based on equality and civil rights.