MONROVIA, Liberia — Just days before the end of her 12-year tenure as Liberia’s head of state, President Ellen Johnson Sirleaf has been expelled by senior members of her political party, who accused her of supporting the opposition candidate and now president-elect, George Weah, in his recent election campaign.

A statement from the Unity Party, released late Saturday, said that Mrs. Sirleaf, Africa’s first female democratically elected head of state, had been expelled because of “several violations and other acts inimical to the existence of the party.”

Among them was her failure to support her vice president, Joseph Boakai, in the election.

Mr. Weah will be sworn into office on Jan. 22, the first peaceful democratic transfer of power in the country since 1944.

The Unity Party’s spokesman, Mohammed Ali, accused Mrs. Sirleaf of using state resources to fund Mr. Weah’s campaign and said that evidence would be disclosed to the public at a later date.