Egypt will hold a referendum on 25 May on a constitutional amendment to allow more than one candidate to stand in presidential elections.
The NDP-dominated parliament passed the amendment on Tuesday
"25 May shall be a day of national pride, as Egyptians... make a new dawn," a statement issued by the ruling National Democratic Party (NDP) said.
The revision was endorsed on Tuesday by an overwhelming majority in parliament.
But opposition groups oppose a change, saying its strict conditions mean only NDP members will be able to stand.
The amendment stipulates that independent presidential candidates must have the support of at least 65 out of a total of 444 MPs - 90% of whom are from the NDP.
Political party candidates have fewer restrictions, but the parties face the hurdle of being recognised by a NDP-dominated committee.
The main legal opposition party, al-Wafd, says it will boycott the vote and urged Egyptians to stay at home on 25 May.
The banned Muslim Brotherhood called on supporters to vote against the amendment.
Under the existing system, voters could only vote yes or no to a single presidential candidate chosen by parliament.