The deputy opposition leader in Solomon Islands, Matthew Wale, says MP Stanley Sofu has no intention of rejoining the government.
The coalition government has been plagued by defections over the last few weeks and the opposition wants a vote of no confidence in the government.
The Prime Minister's office said yesterday Mr Sofu was still a cabinet minister and due to retake his oath of allegiance in coming days.
But Matthew Wale says Mr Sofu is with the opposition, numbers in parliament remain evenly locked at 24-24 and more government MPs are set to move over.
"At least six people have been talking to us about moving over, expressing their desire to move over. Of those six, four have expressed the fact that they are intimidated from exercising their conscience to move over so we'll see what happens."