The newly formed Tautua Samoa political party, made up of twelve opposition MPs, are calling on two other small parties for a coalition ahead of Samoa's 2011 general election.
The interim chairman of the party, Lealailepule Rimoni Aiafi, told reporters the ruling HRPP cannot be defeated if a coalition is officially established before the next election.
But he says a coalition can be formed after a general election because of the number of seats each party could win in the 49 seat Parliament.
But the Prime Minister, Tuila'epa Sailele Malielegaoi, says the fruits of any successful campaign to topple his government should be judged by voters.
Meanwhile the prime minister has left the country to attend his party's 29th birthday celebration which will be held for the first time in Auckland, New Zealand.