A huge poster of former army chief Abdel Fattah al-Sisi stands tall near Cairo's iconic Tahrir Square, one of thousands that have sprung up across Egypt.

Less than three weeks before the launch of official campaigning for the May 26-27 presidential election, supporters of Field Marshal Sisi, the odds-on favourite, are raring to go.

On television, social media networks or stands selling election merchandise, Sisi is omnipresent, with no stone unturned in unofficial campaigning.

Callers to television talk shows have even recited poems in honour of the clear frontrunner. "Oh you brave knight, we rely on you," one enthused.

Footage of pro-Sisi demonstrations and soldiers in training are all over the Internet. "All the people love you," his supporters gush.

Sisi, who retired from the military to run for election, has been riding a wave of popularity since he toppled Egypt's Islamist president Mohamed Morsi last July.

Millions had taken to the streets in protest against Morsi's turbulent one-year rule. Morsi, who belongs to the now blacklisted Muslim Brotherhood, was Egypt's first civilian and elected president.

Amnesty International says that since his ouster, a police crackdown on supporters of Morsi has left dead more than 1,400 people.

Under Egypt's electoral law, any candidate hoping to run for president needs to collect at least 25,000 signatures.

Egyptian media say Sisi has already raised 10 times the required number of backers, with his campaign offices still being swamped with more offers.

"People keep coming. We won't spoil it for them and turn down their signatures," said accountant Khaled al-Shafei, who has made his office in downtown Cairo available for Sisi's campaign.

Shafei said he has relocated his staff to make space for campaign workers and the Sisi enthusiasts.

The Internet is flooded with posts on Sisi, while sites such as Facebook and Twitter have been buzzing since he announced his candidacy.

Even a picture of a lush garden behind Sisi when he declared his candidacy on television in late March has become a topic of debate.

While popular satirist Bassem Youssef could not resist taking a dig at it, pro-Sisi commentators have lauded its environmentally friendly message.

Photographs of Sisi on a bicycle in a Cairo street have also been a big hit on social networks.

Apple of my eye

But what has really inflamed the social networks is an insulting Twitter hashtag which translates into "vote for the pimp".

A Morsi supporter, in a tweet, urged Egyptians "to vote for the pimp so that when there is an electricity cut, he can give us light from the apple of his eye."

He was referring to a speech in which Sisi praised Egyptians as the "apple of my eye".

But such mockery can exact a heavy price, as was the case for a farmer in southern Egypt condemned to six months in jail for riding through his village on a donkey with "Sisi" sprayed on the animal.

In contrast to all the Sisi paraphernalia seen on the streets, there is none for any of his opponents, including Hamdeen Sabbahi, the leftist leader seen as his nearest rival.

The Sisi brand, meanwhile, has turned into a lucrative business.

Video games, chocolates and cakes have been named after him, while posters of Sisi with tigers, eagles or the late charismatic president Gamal Abdel Nasser are everywhere.

Sisi "identity cards" stating his job description as "saviour of the country" are on sale for one Egyptian pound (10 cents).

Another popular item is a currency note with Sisi wearing a hat or in military uniform, looking up with one elbow resting on a sphinx.

"Anything related to Sisi is going fast," said Medhat Mohamed, a street vendor who sells at least 100 posters a day of the candidate.