A prominent Nigerian lawyer has launched legal action to try to force President Umaru Yar'Adua to cede power to his deputy while he remains hospitalized in Saudi Arabia.

The president of the West African Bar Association, Femi Falana, said Wednesday that cabinet decisions made in the president's absence are illegal because he has not formally given power to Vice President Goodluck Jonathan.

Falana says he filed a suit against the government Tuesday in a federal high court in the capital Abuja. 

The cabinet has dismissed calls for Mr. Yar'Adua to resign.  Justice Minister and Attorney-General Michael Aondoakaa said Tuesday the president can exercise his executive powers from any part of the world. 

He said Mr. Yar'Adua continues to be Nigeria's president until he declares he cannot exercise his presidential powers due to ill health.

President Yar'Adua was flown to a hospital in Jeddah, Saudi Arabia, about three weeks ago after complaining about chest pains.  Officials say he is being treated for pericarditis, an inflammation of the membrane around the heart.

The president is also known to suffer from a chronic kidney ailment, and has traveled abroad several times in the last three years for medical treatment.

Some information for this report was provided by Reuters.