Albert Nicholas has been officially expelled from the Cook Islands Democratic party, eight months after defecting from the opposition to join the governing Cook Islands Party.
Albert Nicholas' switch in March helped the Cook Islands Party shore up their numbers to govern the country, and soon after was made the internal affairs minister.
The Democratic party leader, William Heather, says since then he has made a number of attempts to have Mr Nicholas return to the party, but failed.
"Last week we came to a clear understanding with the executive and the caucus and everybody said, enough is enough. We are no longer going to wait around for him, because we are going to prepare ourselves for another candidate to win the next election."
Under anti-party hopping legislation Mr Nicholas is unable to vote on matters of appropriation or confidence in the Prime Minister.
William Heather says Albert Nicholas should step down and allow a by-election to take place.
"I'd like to ask him to step down because he has been elected as a member for the Democratic. Now he's changed sides, take it back to the people. Let the people decide, let him stand for the CIP, then we will put our member in for the Democratic party, let's see who will win."
William Heather says there are three candidates who have been shortlisted to run for the Avatiu-Ruatonga-Palmerston seat.