13. Petitioner to prove his election.

(a) that in fact, the petitioner or such other candidate, received the majority of the valid votes, or
(b) that, but for the votes obtained by the returned candidate, by election offences, the petitioner or such other candidate would have obtained a majority of the valid votes; the Election Tribunal shall after declaring the election of the Returned Candidate to be void, declare the petitioner or such other candidate, as the case may be, to have been duly elected.