Mohamed ElBaradei, the former chief of the International Atomic Energy Agency, has posted a video message on the social network encouraging supporters to peacefully indicate to the authorities they would like reform, saying that it is the responsibility of the individual to opt for change.

The move will intensify speculation over ElBaradei's plans concerning Egypt's next presidential elections, due in 2011. Such conjecture has been rife since ElBaradei's return to his home country following a career in international diplomacy as head of the UN's nuclear watchdog. The National Association for Change, a group promoting political change, was formed on his return after meetings were held with Egypt's opposition groups.

ElBaradei has said he might stand in the presidential elections if a fair election was guaranteed. However as Egyptian law states that potential candidates must lead a legal party for a minimum of one year and the endorsement of parliament is required for independent candidates, it is not certain that ElBaradei would be approved should he put himself forward as a contender.

President Hosni Mubarak has ruled in Egypt since 1981, and many Egyptians believe that he wants his son Gamal, a banker and head of the ruling National Democratic Party's policy committee, to succeed him.