TAIPEI, Taiwan (AP) — Taiwan’s two main opposition parties have failed to agree on a joint candidate for president, once again throwing into doubt their ability to unseat the ruling party in January’s election.

The Nationalist Party and the Taiwan People’s Party were expected to unveil an agreed-upon candidate at a news conference Saturday. Instead, they announced the need for further consultations after a disagreement over how to use polling data to make the selection.

The failure to agree on a joint candidate leaves current of the Democratic Progressive Party as the frontrunner. He is hoping to succeed President Tsai Ing-wen, who must step down after eight years because of a two-term limit on the presidency.

At stake in the election are Taiwan’s relations with China, which says that the self-governing island must come under its control, and with the United States, which is bound by its own laws to provide Taiwan with the weapons it needs to defend itself. Differences over Taiwan are a .

With both their candidates trailing in the polls, the Nationalists and the Taiwan People’s Party to form a combined ticket with one candidate for president and the other for vice president. The decision on who would get the presidential nod — or Ko Wen-je of the People’s Party — was to be based on a combination of public and internal party polls.

The Nationalists and the People’s Party both said they hope to keep talking but it was unclear whether they would be able to sort out their differences by next Friday, the deadline for candidates to register for the race.

“I still think it is necessary for the main opposition parties to ally,” Ko said. “We will think of a way to find the strongest ticket to win the election. This should be our goal.”

A fourth candidate, the billionaire founder of tech giant Foxconn, has also joined the race.

The incumbent Democratic Progressive Party have favored closer ties with the United States as a way to preserve Taiwan’s separate status from China. The Nationalists said that friendlier ties with China were a better approach, and the Taiwan People’s Party, a relative newcomer to the political scene, likewise backed building amicable relations and mutual prosperity with China.

Tsai’s hard-line approach angered China, which has responded by threatening military drills in the seas and skies around Taiwan. The U.S., in turn, countered by pledging support for Taiwan and maintaining arms sales to its military, further angering China.

“The way that this race has really played out is the presidential candidates trying to sell to Taiwanese voters who will be the safest president, who can ensure Taiwan’s safety and ensure that … we do not head (in a) direction towards war,” said Lev Nachman, an assistant professor at National Chengchi University in Taipei, the capital of Taiwan.

The agreement to form a joint ticket was brokered by former President Ma Ying-jeou, a Nationalist who led Taiwan just before Tsai and improved relations with China during his tenure.

China claims Taiwan, an island about 160 kilometers (100 miles) off its east coast, as its territory. The two split during the civil war that brought the Communists to power in China in 1949, with the losing Nationalists setting up their own government in Taiwan.

Brought to you by