A Vanuatu MP Willie Jimmy says he is shocked by the latest defections of fellow opposition members to the coalition government of Sato Kilman.
Six members of the opposition, including three members of the Union of Moderate Parties, joined the government in the past week.
Mr Jimmy says with no more ministerial portfolios appearing to be available, he is unsure what lured the defectors.
"I was shocked to learn about the move to join the government side and I'm not really sure and I don;'t understand why they moved to government side. I don't see any reason unless you have something really, really good to join the government side."
Willie Jimmy says he is aware of speculation that a government backbencher is lobbying to become Prime Minister.
The leader of the Greens, Moana Carcasses Kalosil, looms as the most powerful government member outside cabinet.
However Mr Jimmy says in his view ni-Vanuatu would be reluctant to have a naturalised citizen as Prime Minister.