What remedies are available in the last instance?

http://www.irishstatutebook.ie/1993/en/act/pub/0028/print.html

Presidentialelections act, 1993

PART V

Presidential Election Petitions

57.(9) At the trial of a petition the High Court shall determine the matter atissue in the petition and, if it does not dismiss the petition, shall, whereappropriate, include in its order determining the matter at issue either—

(a)a declaration of the correct result of the election, or

(b)if it considers that it is unable to determine the correct result of theelection, a declaration that the election or a specified part thereof was voidtogether with a statement of its reasons for making the declaration.

57. (10) Where the court declares that apresidential election was void, a fresh election shall be held in accordancewith this Act and the Minister shall, as soon as may be, make a presidentialelection order in respect of the fresh election.