Taiwan's opposition Taiwan People's Party is expected to field its leader and former Taipei mayor, Ko Wen-je, as its candidate for the presidential election in January next year.
The TPP is the third-largest force in Taiwan's legislature after the ruling Democratic Progressive Party and the Kuomintang, the largest opposition party.
Ko served as Taipei mayor for two four-year terms until last December. He is considered to be one of the presidential hopefuls. Polls show he has a support rate of over 20 percent.
On Monday, Ko filed his candidacy for the primary to decide the party's presidential candidate at its headquarters in Taipei. There have been no other candidate applications.
Some members of the Kuomintang are looking to cooperate with the TPP in a bid to realize a change of government.
But Ko has stressed his resolve to run in the presidential race. He said the TPP can work with any party if it is in the people's interest.
The TPP is expected to decide on Ko's nomination on Wednesday next week. He is likely to hold a news conference on May 20 to explain his campaign platform.
Last month, the ruling DPP named party chairperson Lai Ching-te, who is Taiwan's vice president, as its candidate for the presidential election.