French Polynesia's opposition Tahoeraa Huiraatira party has signed a coalition deal with two minor parties for the April territorial election.
The three are campaigning on a promise not to raise the retirement age next year as planned by the government.
The government led by Edouard Fritch wants to adopt the reform before the polls.
The new grouping, which is led by the Tahoeraa party leader Gaston Flosse, now includes the party of Bruno Sandras who like Flosse has a corruption conviction.
He is certain to be able to stand while Flosse is awaiting a ruling by France's highest court on whether his ban to hold public office will be overturned.
The third party in the Tahoeraa-led coalition is the Here Aia which has its roots in Tahiti's nationalist movement of the mid 20th century.
In the last election in 2013 the Tahoeraa won two thirds of all seats.