Egypt's ruling military has promised a return to the barracks once a new president is elected, but the army's formidable political and economic weight means that such a withdrawal could be an illusion, analysts say.

The Supreme Council of the Armed Forces (SCAF), in charge of the country since a popular uprising ousted longtime president Hosni Mubarak, has repeatedly pledged to hand over the keys of the country by the end of June after landmark presidential polls.

The power transfer will symbolise the end of a turbulent transition period marked by violent protests, with the army accused of orchestrating the violence, maintaining a repressive apparatus and holding on to its privileges.

But the powerful institution insists it has kept its promise to lead the country towards democratisation, touting its ability to maintain a relative stability compared with other "Arab Spring" countries like Libya or Syria.

"The army is the only institution in the country that works. It still enjoys some popularity, it has real economic power while the police is unable to reorganise itself to maintain order," said Tewfik Aclimandos, Egypt specialist at the University Paris I.

"It has the ability to remain an important political actor for many more years," he said.

For Hassan Nafea, a leading Egyptian political columnist, "the role of the army will depend very much on the president to be elected."

If he comes from the old regime such as the ex-foreign minister and former Arab League chief Amr Mussa, or Ahmed Shafiq, the last prime minister to serve under Mubarak, "the army will continue to play an important role, and there will be no reform regarding its role or its place."

If another person wins, "troops would return to their barracks, but an agreement will be needed to ensure the process goes smoothly. Many interests, including economic ones, are at stake, and it will have to be dealt with with tact," Nafea added.

One of the main Islamist candidates, Abdel Moneim Abul Fotouh, has promised to confine the military to matters of defence, but without explicitly saying how this would be done.

The Muslim Brotherhood, which dominates parliament and has fielded Mohammed Mursi, could give a harder time to the army, with which it has historic rivalries.

Over the past few months the Brotherhood has alternately criticised the army and issued ambiguous statements suggesting they can find an arrangement with the military.

"The SCAF considers itself the sole actor possessing the experience, maturity and wisdom necessary to protect the country from domestic and external threats," the International Crisis Group said in a report on the army.

Now, "its objective is to stay in the background yet remain an arbitrator; and shun the limelight even as it retains decisive influence," the think tank said.

The army has been the backbone of the Egyptian system since the fall of the monarchy in 1952, with all the country's presidents since then hailing from military backgrounds.

Rumours and debates in recent months appear to indicate that the army's wants to keep its budget a secret by remaining exempt from parliamentary scrutiny, maintain control of military-related legislation and secure immunity from prosecution.

These issues could be addressed in the country's new constitution, the drafting of which has slowed down due to political obstacles.

The army is also protective of its vast and opaque financial empire, which includes countless companies in varied fields, from construction to hospitality, food and cement.

General Mahmoud Nasr, member of the SCAF, warned in March that the military "will not allow any interference, from anyone, in the economic plans of the army."

Since a peace deal signed with Israel in 1979, the Egyptian army also receives $ 1.3 billion from the United States in annual assistance.