A special parliamentary session has begun in Vanuatu, to determine whether the opposition or the government should be in power.

Today's vote is between the governing alliance led by Prime Minister Sato Kilman and the opposition grouping of Serge Vohor.

Mr Vohor was the Prime Minister for a brief period, following a no-confidence vote in April that ousted the Kilman cabinet from power.

But an appeals court ruling overturned that decision, saying Mr Vohor was one vote shy of attaining an absolute majority of 27 votes in the 52 member parliament.

Both parties have said they are confident they have the numbers to form government.

Vanuatu journalist Gabriel Vusilai has told Radio Australia's Pacific Beat he believes the government could have the numbers.

"Maybe the government will still topple whatever the Opposition intends to table this morning in terms of the motion of no confidence," he said.