RNZ reports the former MPs were among the 14 sentenced to three years in prison last year on corruption and bribery charges.
The charges came after the MPs were pardoned of the offences by the speaker of parliament, Marcelino Pepite, who at the time was the acting president.
The president, Baldwin Lonsdale, overturned the pardons on his return to the country, and the Supreme Court later threw out the MPs' bid to have that decision dismissed.
Under the Vanuatu's law, the penalty for conspiracy is seven years in prison.
