After weeks of prevarication, Field Marshal Abdel Fattah al Sisi finally bowed to the inevitable and announced he would be a candidate in presidential elections later this year.

His candidacy was an open secret and he was the clear frontrunner but it was the end of last week before he ended the suspense and allowed his name to go forward.

"Yes, it has been decided, I have no choice but to meet the demands of the Egyptian people," Sisi said. "I will not refuse this request."

The waiting has ended but the youthful-looking head of Egypt's armed forces still faces a long battle to turn himself into a legitimate leader.

On the face of it his popularity seems to be unassailable. Earlier last week senior officers in the armed forces gave him unconditional backing, and recent polls suggest he enjoys the support of a wide cross-section of Egyptian society.

That is not least because he was instrumental in creating the conditions which led to the removal of the previous incumbent, president Mohamed Morsi, the greatly disliked leader of the Muslim Brotherhood, now outlawed as an illegal terrorist organisation.

So it should be a walkover for the 60-year-old army officer who also acts as Minister of Defence and was promoted to field marshal last month. His popularity is also a reflection of the high esteem in which the armed forces are held, being regarded as protectors of the people and a bulwark against the Brotherhood.

Hailed as a popular hero - "the new idol of the Nile valley", is one media description - Sisi is certainly the man of the moment and it is difficult to see any credible presidential rival standing in his way.

But, perversely, the virtues that turned the field marshal into a politician are also a potential barrier to achieving power. For all he is revered for restoring a semblance of calm after Morsi's departure, he is also disliked by many moderate Egyptians for the violence after Morsi's ousting.

Terrorism is still an everyday fact in the country. Within the past fortnight Islamist militants have detonated a car bomb outside Cairo's security headquarters, gunned down a senior Interior Ministry official in broad daylight and deployed a portable surface-to-air missile to shoot down a military helicopter over Sinai

This kind of action suggests military competence from combat experience, and security experts to believe the violence is being fanned by extremists from Egypt coming back to the country after fighting in Syria or Afghanistan.

Last week in Washington John O Brennan, director of the CIA, warned returning battle-hardened jihadists could form a credible threat to the wellbeing of Egypt.

"The number of attacks has gone up certainly over the past six weeks," he told a House hearing, "and some senior-level Egyptian officials have been killed at the hands of these terrorists."

Such tactics are hard to counter and a heavy-handed response often makes matters worse. In recent fights between the army and the Brotherhood 1000 of their number have died and many more have been locked up. But hundreds of thousands are still active and despite repression the Brotherhood has not disappeared.

An influential poll revealed that around half of Egyptians held Sisi responsible for the toppling of his predecessor and the violence that followed, and that "the continuing violence has taken a toll".

For Sisi and his supporters the only positive news from the poll was the finding that a majority of Egyptians agreed that the Muslim Brotherhood should be banned.

When judging Sisi's potential there are other factors to take into consideration. In addition to understandable fears about the worsening internal security situation, most Egyptians worry about the parlous state of the country's finances and the deterioration of the domestic economy.

Standards of living are appreciably lower than they were three years ago when Mubarak fell from power, and inward investment has slumped thanks to the political uncertainty.

Added to this is a widespread feeling that the ethos of the Arab Spring revolution has been betrayed and there is nothing to show for the sacrifices of those who struggled for political change three years ago.

In no other country in the Middle East is this feeling more bitter than in Egypt, where the military overthrow of a freely elected Islamic Muslim Brotherhood government seemed to prove that power could never be won through the ballot box and that the violence of jihad was the only credible response.

If none of these issues are addressed, or if Sisi fails to come up with working ­solutions which have an immediate effect, his present popularity will count for nothing. As recent events have shown in Egypt, public opinion is volatile.

Mubarak retained support right up to the end of his presidency and Morsi was at least elected by democratic vote. Sisi's political inexperience could also weaken him but against that he has shown himself to be an adroit operator - his vision of the military and the people of Egyptian being as one and standing together after the ousting of Morsi revealed a sure hand in dealing with public relations.

This was confirmed by the canny way he used public discontent to his advantage. Having encouraged Egyptians to make their voices heard last summer when disaffection with the Muslim Brotherhood was growing daily, he made sure everyone understood that, if necessary, the army would intervene to restore order.

When Morsi was driven from power last July he was quick to make it clear the army had acted in the country's best interests and while he felt "the need to remain distant from political action" he wanted to get across the message that the army had to act to save the people of Egypt from catastrophe.

Sisi has let it be known that his ­political ambitions are not driven by personal vanity but arise from "a call that demands compliance". Those who know him well admit that behind the devout Muslim who rises each day at 5am for prayers there is a charismatic leader who misses little and has an easy capacity to get on with colleagues. That could be a trump card.

When analysing Sisi's proposed move into politics, Egyptian observers are fond of quoting a well-worn proverb which they believe applies directly to the field marshal: "No matter how bitter the prescription of reforming the economy is, if it comes from someone the people love, they will endure it."