The former Solomon Islands Prime Minister, Gordon Darcy Lilo, who lost his seat in last year's election, has filed an election petition against his successor, Jimson Fiau Tanangada.
The Island Sun Newspaper says Mr Lilo's petition is one of 15 scheduled for a pre-trial conference at the High Court next Thursday.
Of the 15, four have been filed by MPs who lost their seats and 11 by other losing candidates.
The paper says most petitions allege bribery, treating and undue influence.
Since independence 36 years ago, only a handful of election petitions have been successful and only one has resulted in the mover winning a subsequent by-election.