CAIRO (AFP) - Egypt's army chief Abdel Fattah al-Sisi stepped closer on Saturday to confirming a widely anticipated presidential bid, saying he would stand in elections if there was a popular demand, state media reported.

Sisi is easily the most popular leader in Egypt after toppling Islamist president Mohamed Mursi in July, and military officers have told AFP he had support within the army to stand in the election due to take place later this year.

His comments come just days ahead of a referendum on a new constitution, the first in a series of polls the military-installed government says will restore elected rule following Mursi's ouster.

"If I nominate myself, there must be a popular demand, and a mandate from my army," the state newspaper Al-Ahram quoted him as saying at a conference with Egyptian officials.

Although he enjoys wide support for toppling the unpopular Islamist, Sisi is reviled by Mursi's supporters for what they call a "coup" against Egypt's first freely elected president.

Mursi's Muslim Brotherhood has called for a boycott of the referendum on Tuesday and Wednesday, which its opponents view as a plebiscite on the legitimacy of Morsi's overthrow.

The Islamist movement is reeling from a crackdown that has killed more than 1,000 people in street clashes since Morsi's ouster, and left thousands in jail.

An official close to Sisi told AFP a large turnout to approve the constitution would be an "indicator" of whether voters wanted Sisi as president.

The official said the general had not made up his mind but feels he "would not have the luxury or choice" to stand aside in the election if there is a palpable demand for him to run in the poll Al-Ahram reported the audience broke into applause at Sisi's comments and chanted "we are all with you".

A member of the audience confirmed the comments to AFP.

At the conference, Sisi also urged Egyptians to participate "in force" in the referendum.

A pro-Mursi coalition said it would hold protests against the "illegitimate constitution".

The official close to Sisi told AFP the general would be "obliged" to stand in the election if he felt the people demanded him as president.

"He will never let the people down," he added, speaking on condition of anonymity.

Sisi is wildly popular among a majority of Egyptians who had rallied in the millions demanding Mursi's resignation before the military overthrew and detained the Islamist leader.

Most of the leading former candidates who lost to Mursi in the 2012 election have said they would stand aside if Sisi chose to run.

Beleaguered by three years of instability following the overthrow of president Hosni Mubarak in the 2011 uprising, many Egyptians yearn for a strong leader who would fix the economy and restore security.

Sisi, a former military intelligence head, was little known before Mursi appointed him as his defence minister and army chief in 2012, after purging senior officials whose loyalty he doubted.

Military officers said the 59-year-old general had attempted to advise Mursi during his presidency, but the Islamist insisted on taking unpopular decisions that alienated his secular opposition, the judiciary and security services.

Mursi's supporters accuse the army of backing a "counter revolution" by Mubarak loyalists embedded in the state's bureaucracy.