Egypt's ruling military is not fielding a candidate in next month's presidential election, the Supreme Council of the Armed Forces (SCAF) chief Field Marshal Hussein Tantawi said on Monday.

"The armed forces do not have a candidate in the next presidential election," the official MENA news agency quoted Tantawi as saying, adding that the army was "neutral" towards all candidates.

Figures from the regime of former president Hosni Mubarak, who stood down early last year after a popular uprising, have been trying to make a comeback, with Mubarak's former spy chief on Sunday declaring his candidacy for the post.

Omar Suleiman is regularly painted as a favourite of the SCAF, which has ruled Egypt since Mubarak's February 11, 2011 resignation.

Suleiman on Monday lashed out at the Muslim Brotherhood, which dominates parliament and is widely tipped to take the top job too, and insisted his candidacy would restore stability.

A sworn enemy of Islamists before last year's revolution which brought down Mubarak, Suleiman vowed not to drop out of the May 23-24 election despite alleged threats from Islamists.

The Brotherhood's candidate, Khairat El-Shater, likened Suleiman's candidacy to an attempt "to steal the revolution" and warned it could set off another round of huge street protests.

Apart from Shater, the candidates include former Arab League chief Amr Mussa and ultra-conservative Islamist preacher Hazem Abu Ismail. Suleiman himself registered less than half an hour before the deadline.

The powerful Brotherhood had repeatedly vowed not to field a candidate before making a dramatic U-turn.