Vanuatu's former prime minister, Barak Sope, says he is confident that the Supreme Court will this week rule in his favour and reinstate him in parliament.
The court is expected to rule on his challenge to the speaker's decision to declare his seat vacant.
Last year, Mr Sope was sentenced to three years in prison for fraud but he was pardoned by the President Father John Bani after just serving three months.
The government claims he cannot be reinstated as MP because the pardon only became effective in November after he had served part of his jail sentence.
But Mr Sope is arguing that his pardon applied to when he was jailed in July.
"I'm very hopeful because the pardon that I received is a full pardon. It's a very interesting case, it's the first one in Vanuatu's history, it's a constitutional case and both sides gave good arguments."
Mr Sope say if he loses in court he will contest his seat in a by-election.