The BBC's Barnaby Phillips: Democracy offers a last hope to Nigeria

Colonel Mohammad Marwa is one of the most powerful men in Nigeria.

For three years, he has been the Governor of Lagos state and regularly travels through the city in an 18-car convoy.

Colonel Marwa is a soldier carrying out the duties of a civilian politician.

Queues for petrol stretch round the block

No one denies the Colonel has been an effective administrator, but he faces huge problems.

At the city's petrol stations queues stretch for a kilometre. Nigeria is one of the world's leading oil producers but it can not provide enough for its own citizens.

A Northerner like many of the Nigeria's ruling military elite, Colonel Marwa, is genuinely popular with the southern Yoruba people he governs.

He may now enjoy a high profile but says he is happy to return to barracks under civilian rule and that the democratic process must be sustained.

Military limitations

Colonel Marwa: "We know that everybody is tired of us."

"If they make mistakes and so on, give them the opportunity to be voted out, so that other people are voted in who will do better job," he says.

"We know that everyone 's tired with us, and we in the military are also tired of being in governance.

Operation "Sweep", aimed at cutting Lagos' frightening crime rate is perhaps Colonel Marwa's main achievement. But it also shows the military's limitations.

Although 24-hour checkpoints and patrols have reduced crimes significantly, innocent civilians have also been killed by "trigger-happy" security forces.

Bola Tinubu, the Colonel's civilian successor who takes over in May, has a different background.

Lagos chaos

Operation Sweep: A crack-down on crime

A political exile until last November, he is poised to become the first civilian to run Lagos for 15 years. International businessmen are already beginning to travel to Lagos to court him.

A former executive with the oil company Mobil, Mr Tinubu aims to apply technocratic expertise to the chaos of Lagos.

"There are going to be problems and frustrations along the line," he says. "But if we are consistent in application of our policies, if we are patient, if we persevere, we will definitely get there."

The realities of Lagos may thwart Mr Tinubu's ambitious plans; the city is collapsing as fast as it grows, disappearing under a mountain of rubbish.

Bold action has been taken before.

One huge rubbish incinerator cost millions. It never worked.

Grand projects

Bola Tinubu: Faces an uphill task

Commissioned by a previous civilian governor it is proof that the military does not have monopoly on mismanagement.

As Mr Tinubu's advisers inspect the derelict site of incinerator, it is a thought they should bear in mind as they formulate plans for a Lagos metro system.

Successive governments have spent millions in an attempt to leave their mark in the city, leaving grand projects that were either never finished or never worked.

Mountains of rubbish burn in the streets

Meanwhile life for ordinary people in Lagos has got steadily worse. But, for the moment, at least, democracy offers some hope.

State governors were elected in January and now campaigning is finally under way for the crucial national elections.

The people will have their say.

Previously Lagos and Nigeria have been failed by both military and civilian rulers.