TAIPEI - The leader of a small Taiwanese party who has been in talks with the main opposition party for a joint presidential ticket showed no signs of backing down on Sunday in a dispute deadlocked over who runs as president and who for vice president.

The issue of China, which views Taiwan as its territory, looms over the Jan. 13 parliamentary and presidential elections. China has stepped up military and political pressure, including high-profile war games, to press the island to accept the sovereignty claims that Taiwan rejects.

After weeks of sometimes acrimonious talks on joining up for the presidential election, the Kuomintang (KMT) and the much smaller Taiwan People's Party (TPP) agreed on Wednesday to look at an aggregate of opinion polls to decide which party's candidate would run as president and which as vice president.

The parties on Saturday failed to reach agreement on how to interpret opinion polls and thus decide on who will stand for which position. Candidates have to register with the election commission by Friday, Nov. 24.

Speaking at an election rally on Sunday, TPP chairman Ko Wen-je said he would not go against public opinion or "abandon" his supporters and would work to bring together all the forces that could be united.

"But I will continue to fight to the end as the TPP's presidential candidate," said Ko, a former Taipei mayor.

The ruling Democratic Progressive Party's (DPP) candidate, Vice President Lai Ching-te, has for months led most opinion polls to be Taiwan's next president, leaving the KMT's Hou Yu-ih and the TPP's Ko to battle it out for second place.

Speaking to senior party officials, KMT Chairman Eric Chu said it was "everyone's common goal" to unite, and the party will make efforts to do so until the last minute.

China detests frontrunner Lai, regarding him as a separatist, and has rebuffed repeated calls from him for talks. Hou especially has vowed to renew dialogue with Beijing, and says Lai is a dangerous supporter of Taiwan independence.

Some opinion polls have shown that if Hou and Ko team up, in whatever combination, they would beat Lai and his presumptive running mate, Hsiao Bi-khim, Taiwan's envoy to the United States.

Lai is due to announce Hsiao as his running mate on Monday.

(Reporting by Ben Blanchard; Editing by Tom Hogue)