Egypt is poised to return to an era of strongman leadership, almost three years after the fall of former general Hosni Mubarak, after the army's governing council gave its blessing for army chief Abdel Fatah al-Sisi to run for the presidency.

Sisi has been discussed as a potential head of state ever since he ousted Egypt's first democratically elected president, Mohamed Morsi, last July, and replaced him with the judge, Adly Mansour. The move made Sisi so popular among certain sections of the population that he is likely to win any election by a landslide.

For months, Sisi made no clear indication of his intentions, and on Monday night he still had not personally confirmed his candidacy. But a carefully choreographed series of moves made his transition to frontline politics seem all but complete.

In the morning, Mansour promoted him to the honorific title of Field Marshal – a move that often foreshadows an Egyptian officer's resignation from the military. Eight hours later, the supreme council of the armed forces finally announced that Sisi had their go-ahead to run for office.

"The supreme council of the armed forces cannot but look respectfully and honourably on the desire of the great Egyptian people in nominating General Abdel Fatah Sisi for the presidency," read their statement.

The statement said Sisi had thanked the military leadership for allowing him "the right to respond to the call of duty".

Sources close to Sisi said he was merely waiting for nominations to open officially before declaring his hand himself. Interim president Mansour announced on Sunday that presidential elections would take place by the end of April, but the electoral high commission has not yet formalised the process.

"I very much expect him to run," said former general Sameh Seif Elyazal, once a colleague of Sisi's at military intelligence. "They just have to wait until the presidential election high commission announces officially the dates."

A serving senior officer also said Sisi was waiting for the nominations to open. "My expectation is that he will go for it," said the source, speaking anonymously, "because most of the public would be depressed if he did not – they don't see any other civilian candidates."

Hundreds of thousands of Sisi supporters filled Cairo's Tahrir Square on Sunday to call for the then-general to run. Sisi-themed memorabilia – ranging from chocolates to underpants – can be bought across Egypt, while a group of Sisi fans claim to have collected millions of signatures calling for him to lead Egypt. "His promotion has made the Egyptian people so happy today," said Maha Abdelazeez, the campaign's founder, on Monday.

But public sentiment is hard to quantify in Egypt. Over 98% of participants voted for Egypt's new constitution this month, a sign of strong support for Sisi.

But only 38.6% of those eligible to vote took part. Morsi supporters detest the field marshal for presiding over a campaign of oppression that has seen over a thousand Morsi supporters killed, and thousands more arrested. A Zogby poll from September suggested Egypt was roughly split on Sisi's decision to topple Morsi on July 3 last year, following days of mass protests.

Secular activists expressed their frustration at the likely candidacy of another soldier, three years after they forced the removal of Hosni Mubarak. Sisi headed military intelligence under Mubarak, and was a member of the military council that drew criticism for the heavy-handed way it ruled Egypt following Mubarak's overthrow.

"It's no good – it sends a message to the people that 3 July was a coup," said Ahmad Abd Allah, an activist who called for the fall of both Mubarak and Morsi. "We didn't go through 25 January 2011 or 3 July 2013 for this."

Analysts warned that while Sisi currently enjoyed widespread popularity, the problems besetting Egypt were so great that he might come to regret leaving the army.

"On a personal level it is a huge gamble," said Michael Hanna, an Egypt analyst at the Century Foundation. As president, Sisi "no longer has civilians to absorb the anger of the public when the situation doesn't improve. He's got a lot of public support, and he would win in an election tomorrow. But Egyptians have proven themselves fickle in their support for public figures."

The decision was also a gamble for the military itself, since any failure by Sisi would also tarnish them as an institution, Hanna argued. "But it is hard to imagine the military doing to Sisi what they did to Morsi. It happened to Mubarak after many many years, in very exceptional circs, but it is difficult to see that happening again."

Senior officers are very supportive of Sisi's candidacy, the senior officer told the Guardian. "Of course the presidency is a poisoned chalice," he said. "But of all the [potential] presidents, he is the only one who can solve those problems. He is a fighter."