Vanuatu's opposition is preparing a motion of no-confidence to be tabled within a week.
Barak Sope, who was dumped as Agriculture minister this week, says a number of government backbenchers are dissatisfied with the government's policy on kava exports and are willing to back the motion.
This follows last week's order by the prime minister, Ham Lini, for Vanuatu's Commodities Marketing Board to take over duties of certifying and exporting kava.
Mr Sope says he was sacked by Mr Lini because he made it clear he feels the Prime Minister is favouring his supporters in the allocation of kava exporting licenses.
"With the reform programme, the government, the opposition and everyone has said that to develop the economy of Vanuatu, it must be private-led. Now the monopolisation of kava is going contrary to this policy. They're using the kava thing as a political means of getting support."
Barak Sope says with his four Melanesian People's Party MPs, the opposition has about 22 MPs in the 52-seat parliament, and could entice more to back the motion.