Vanuatu's prime minister, Edward Natapei, is expected to face a leadership challenge at his Vanuaaku Party's Congress on Tongoa next week.
The move is spearheaded by a former lands minister, Harry Iauko, who claims to have the support of most of the party's sub-committees.
Mr Iauko was sacked last year when Mr Natapei reshuffled his cabinet to accommodate the Alliance group of the current deputy prime minister, Sato Kilman.
If he can succeed Mr Natapei as party president, our correspondent says there is likely to be a change of government leadership.
Mr Iauko has chartered a plane and ships to transport the party sub-committees which are in his side to Tongoa.
He's previously initiated a motion of no confidence against Mr Natapei in 2005.
