Vanuatu's former prime minister, Barak Sope, is expected to know on Thursday whether he is still a member of parliament.
The Supreme Court in Port Vila is expected to rule on Mr Sope's parliamentary status after he challenged the speaker's decision to declare his seat vacant.
Mr Sope, who was sentenced to three years in prison on charges of fraud last year, was controversially pardoned by President Father John Bani, after serving just three months.
Mr Sope's legal team believes he should maintain his parliamentary seat following an appeal filed against his conviction within 30 days.
Under Vanuatu laws, members of parliament lose their seat if they are sentenced to more than two years in jail.
The government has questioned the way Mr Sope was pardonned, but the opposition is supporting his return to parliament.