Nigeria's National Assembly meets Tuesday in a session that will consider a request by state governors to make the vice president the country's acting leader because of the prolonged medical absence of the president.
Lawmakers will discuss the health of President Umaru Yar'Adua, who has not been seen in public since late November when he left for medical treatment in Saudi Arabia.
Because the president did not formally notify parliament of his absence, official power has not passed to Vice President Goodluck Jonathan, raising questions about who is in charge here in Abuja.
While the vice president has made executive decisions during the past 10 weeks - including sending troops to the city of Jos to put-down religious violence - there is growing pressure to make that de facto transfer of power official.
The National Assembly meets Tuesday in a political landscape considerably changed from its vote last month backing the president.
Nigeria's powerful state governors now say they believe a temporary transfer of authority is in the nation's best interest. And they want the national assembly to make Vice President Jonathan acting leader.
It is unclear whether the assembly can do that as the 1999 constitution says that short of impeachment, power is only transferred at the president's request.
For the first time in this constitutional crisis, a member of the president's Cabinet says he should make that request. Information Minister Dora Akunyili will push that motion again at a Cabinet meeting scheduled for Wednesday.
But that motion may be moot if the National Assembly acts, or, as some members of the ruling party suggest, President Yar'Adua agrees to transfer power before lawmakers ask him to do so.
In the president's absence, Foreign Minister Ojo Maduekwe says affairs of state have proceeded without incident.
"There is no power vacuum. There is no leadership vacuum," he said. "The vice president functions. And this vice president is functioning fully on behalf of President Yar'Adua."
But the president's absence has had an impact both domestically and regionally. The planned sale of new offshore oil blocks has been postponed. Some rebels in the Niger Delta say they have renewed their armed conflict, in part, because President Yar'Adua's much-heralded amnesty program has stalled.
The annual summit of the Economic Community of West African States has twice been postponed because President Yar'Adua is not available to carry out his duties as its leader.
Despite that absence, ECOWAS mediation of Guinea's political crisis has made progress with a new power-sharing deal between the military government and civilian politicians. But regional diplomats say the delayed summit has slowed momentum on additional action against Niger's president, who extended his term last year in a controversial referendum.