Egypt will hold a presidential poll this year before parliamentary elections, interim president Adly Mansour said in a move seen to benefit army chief Abdel Fattah al-Sisi.

The election process would have to start before mid-April, according to a timetable included in a constitution adopted in a referendum this month.

The military-installed government said the elections will restore democratic rule by the end of 2014, after the army toppled Islamist president Mohammed Mursi last July.

It had initially planned parliamentary elections first.

It has rescheduled the polls in line with demands for a president to be elected before the legislature, Mr Mansour said.

In an address on state television, he said: "I have taken a decision to amend the roadmap of the future by starting with a presidential election." 

Holding the presidential election first is expected to influence the outcome of the parliamentary poll.

Candidates for the legislature are likely to rally around the elected president to improve their chances at the ballot box.

This would mean a friendlier legislature for the president, analysts say.

General Sisi is the only serious potential candidate at the moment, although he has yet to announce his widely anticipated candidacy.

The powerful army chief has said he would stand in the election in case of "popular demand".