Nigerian President Umaru Yar'Adua says corruption is widespread in Nigeria and efforts to tackle graft must take on a new urgency. 

Speaking Wednesday at the launch of an anti-corruption campaign, President Umaru Yar'Adua called for a war on corruption.

"Corruption is Nigeria is a major national problem," he said. "Corruption is endemic in this country, and there is absolutely no way this nation can achieve its potential until and unless this evil, this challenge, is confronted frontally by all Nigerians.  We need to declare a national war on corruption that involves everybody in this country."

Nigeria regularly ranks among the most corrupt countries in the world - a deterrent to foreign investment and impediment to growth.  Nine out of ten Nigerians survive on less than $2 a day, their lives blighted by poor infrastructure and a lack of public services resulting from decades of endemic corruption.

Analysts say the country has earned the equivalent in today's terms of nearly 1.2 trillion from oil production over the past four decades.  But Nigeria's public health system, education and roads are all in shambles, largely due to corruption and mismanagement during decades of military rule which ended in 1999.

But even after nearly a decade of civilian administration Nigerians have little to cheer about.

Yar'Adua took power last year pledging zero tolerance for corruption, but campaigners have questioned his commitment to wage war against graft in Africa's largest oil producer,

President Yar'Adua says the important first step in fighting official corruption in Nigeria is the removal of immunity from prosecution enjoyed by top officials.

"Some of the steps and measures that we may have to take in order to entrench this fight against corruption is to look at some of our laws and I want today, to call for the abrogation of the constitutional provision of immunity for president, vice president, governors, deputy governors," he said. "And I want all Nigerians to join me in this cause."

The country's anti-corruption agency, the Economic and Financial Crimes Commission, says it recovered more than $4 billion from fraudsters in the past six years.

About 10 former Nigerian governors have been charged with graft and money laundering since they lost their immunity from prosecution when their terms ended in May, 2007.