Reports from French Polynesia say a member of the assembly for the Marquesas islands is set to switch side for the third time in nine months.
The Tahitipresse news agency says Jean-Alain Frebault has appeared at a meeting of Oscar Temaru's coalition in what is seen as a bid to join it less than a week before the assembly is due to elect a new president.
Mr Frebault was elected to the assembly last year on the list of Gaston Flosse's Tahoeraa Huiraatira Party but voted for Mr Temaru when he was elected president last June.
Mr Frebault then switched back to the Tahoeraa and voted for Mr Flosse when he was re-elected president in October.
If Mr Frebault switches side again, Mr Temaru will have the numbers to win the presidency without the support of the members of the Alliance for A New Democracy.
Nominations for next week's presidential election have to be filed by tonight.