The Vanuatu government is expected to face an opposition motion of no confidence in parliament today.
The motion was prompted in large part by the prime minister's controversial decision to grant diplomatic recognition to Taiwan.
That decision was rejected by the Council of Ministers but Mr Vohor overrode that criticism, reshuffling his cabinet and removing one of his critics, Barak Sope, from the foreign affairs portfolio.
Mr Vohor has also faced recent criticism for rushing through controversial amendments to the constitution.
The changes include more power for the prime minister and a one-year grace period prior to and after an election when votes of no confidence can't be brought against the government.