The Papua New Guinea Prime Minister Peter O'Neill has called reports of eight government MPs joining the opposition the actions of desperate people.
Mr O'Neill is quoted by the National newspaper saying the opposition statement cannot be trusted - that they are just "desperate people calling all sorts of names and numbers".
Shadow minister for justice, Kerenga Kua, said the names of the eight MPs would be revealed today.
The opposition is planning a vote of no confidence in Mr O'Neill when the grace period ends on 5 February, and needs 56 votes in the 111 seat House.
The opposition deputy leader, Tim Masiu, said they were in discussions with a number of government MPs and believe they will get the numbers needed.
The new session of parliament begins this afternoon.
Meanwhile, the second biggest party in the government, the Pangu Party, said it remained intact with its 14 MPs pledging their loyalty to Mr O'Neill.