Some of the Solomon Islands ministers and MPs who quit the government last month are now in the Parliamentary Independent Group.
They are Dr Derek Sikua, Ishmael Avui, Commins Mewa and Mathew Wale.
The Political Parties Commission has registered them under the National Parliamentary Coalition Opposition Group.
The opposition now consists of the Democratic Alliance Party, the Independents, the Solomon Islands Rural Advancement Party and an MP of the People's First Party.
The four Independents were members of the United Democratic Party.
The Commission maintains ministers and backbenchers of the Kandere Party who also resigned from the government remain as members of the government as they have not resigned from their party.
The prime minister Manasseh Sogavare says the opposition is continuing with efforts to topple his government despite withdrawing a proposed motion of no confidence recently.