20100101

ABUJA (Reuters) - Nigerian Vice President Goodluck Jonathan said on Friday he was hopeful that President Umaru Yar'Adua, who is in hospital in Saudi Arabia, would return soon and continue to govern Africa's most populous nation.

Yar'Adua has been absent for more than a month and Jonathan has been presiding over cabinet meetings. But executive powers have not officially been transferred, leading to questions over the legality of government decisions.

Political analysts, senior lawyers and a former U.S. envoy have warned Nigeria is on the brink of a constitutional crisis. The Bar Association has brought legal action to try to compel Yar'Adua to temporarily hand over power.

But in a wide-ranging New Year's Day address to the nation, Jonathan said "the ship of state continues to sail" and that "the nation remains united and driven by a common purpose".

"Although Mr President has been away from us for sometime on account of a medical condition, he has maintained sustained interest and optimism (in state affairs)," Jonathan said.

"We are hopeful Mr President would return to us before long to continue his good works, with renewed vigour and vitality."

Lawyers and members of the opposition who have challenged Yar'Adua's failure to formally transfer powers say affairs of state are already being affected.

A new chief justice was sworn in on Wednesday in Yar'Adua's absence, leading legal experts to question the legality of the ceremony. The top judge is a key position because he would in turn swear in a new president, legal experts say.