The speaker of the Vanuatu parliament has declared the seats of the prime minister the deputy prime minister and 16 other government MPs vacant.
RNZ Pacific understands a Supreme Court challenge is already being prepared.
Gracia Shadrack made his declaration as parliament prepared to hear two votes of no confidence this morning.
One was a government motion to have the Speaker removed, that feud saw 19 government MPs, including prime minister Bob Loughman, boycott parliament for three days last week.
Mr Shadrack argued that a constitutuional provision ruled that a seat be declared vacant if an MP is absent from parliament for three consecutive sittings.
The same provision was used last June to suspend 22 members of the opposition, which was challenged in the Supreme Court.
The government withdrew the suspension before it could be heard, but the Supreme Court ruled in the opposition's favour.
An opposition motion of no confidence in the government was also due to be heard this morning.