The Papua New Guinea opposition leader, Patrick Pruaitch, has taken his National Alliance Party into the James Marape government.
Mr Marape said he commends Mr Pruaitch for putting aside personal interests for the sake of the country.
He said the move brings additional firepower and experience as the government works to make "Papua New Guinea the Richest Black Christian Nation where no child is left behind".
The National Alliance switch follows other opposition MPs joining the government two weeks ago, while last week the prime minister asked the People's National Congress, headed by former prime minister, Peter O'Neill, to leave the government benches.