The three have launched a campaign to collect a million signatures in support of changing the way Egyptians vote for a president.

Feminist author Nawal Saadawi, liberal sociologist Saad al-Din Ibrahim and former member of parliament Muhammad Hasanain said in a statement on Monday that the petition to parliament would be the first step in a coordinated campaign to change the system.

"We, the undersigned, call on the People's Assembly [parliament] to allow more than one candidate to compete for the position of President of the Republic in free direct elections starting with the presidential elections of 2005," the petition reads.

Saadawi said the candidates and their supporters would publicise their signature campaign with meetings across the country to mobilise people for change and explain the constitutional issues to them.

No legal right

"This is just the beginning," Saadawi added. At present, parliament chooses a sole presidential candidate whose name then goes to a popular referendum. President Husni Mubarak's ruling National Democratic Party dominates parliament.

NDP officials say parliament will nominate a candidate in May for a referendum in September. No one has said who the NDP candidate will be but Egyptians assume that Mubarak, 76 and in power since 1981, will seek a fifth six-year term.

Egyptians believe Gamal Mubarak
is being groomed to take over

Unless parliament amends the constitution, the three candidates will have no legal right to challenge Mubarak and their names will not appear on the referendum ballots.

Multi-candidate elections for the presidency are a consensus demand of the Egyptian opposition. The NDP says it will not consider changing the system until after this year's elections.

The petition is the latest of a series of public challenges to the system which has prevailed in Egypt since the overthrow of the monarchy in 1952.

In December, several hundred people demonstrated openly in central Cairo against a new term for Mubarak or any attempt to install his son as his successor.