What remedies are available in the last instance?

Electoral Act 2006, 104

At the conclusion ofthe trial of an election petition, the High Court shall determine whether therespondent, or any other, and which, person, was duly elected, or whether theelection to which the election petition relates was void, and the Registrarshall as soon as may be, submit a copy of such determination to the Speaker ofthe National Assembly and to the Commission.

(2) Where the HighCourt determines under subsection (1), that the respondent was duly elected,the election shall be and remain valid.

(3) Where the HighCourt determines under subsection (1), that the respondent was not duly electedbut that some other person was duly elected, that other person shall be deemedto have been elected accordingly.

(4) Where the HighCourt determines under subsection (1), that the respondent was not dulyelected, and that no other person was duly elected, at the election concerned,the vacancy in the membership of the National Assembly in respect of which thatelection was held shall be deemed to continue until duly filled.

http://aceproject.org/regions-en/eisa/ZM/Electoral%20%20Act%202006.pdf