Analysts said Han would also have to convince voters that he can improve Taiwan’s economy and safeguard the self-ruled island’s sovereignty.

Speaking on a radio talk show on Tuesday, Gou’s spokeswoman Amanda Liu said he needed time to reflect on the results but dismissed as “fake” the rumours circulating during the primaries that Gou might run as an independent.

Liu said the speculation could have lost him some support, but would not comment on his next step.

“The past three months have been very hectic for him and he will need time to reflect and for [this] to sink in,” Liu said.

Late on Monday, Gou posted messages on Facebook saying he had no regrets about running in the primaries and had learned from it.

“The brief experience was a precious lesson to me, which I hope may inspire others,” Gou wrote.

“That is, no one should lose heart but everyone should be responsible for their own choices. Even if people in the world are laughing at and ridiculing you, please don’t give up your dream.”

He added: “It’s not easy for the brave to lead a fearless life, but [you] can do it.”

Analysts said that without clear support from Gou, Han would have to work harder to reinforce unity within the opposition party, which had ruled Taiwan for decades in the past.

“The first thing [Han] must do is to ensure unity within the party,” said Chang Ruay-shiung, president of the National Taipei University of Business.

Chang added that Gou’s support could affect Han’s election bid since the tycoon might team up with Taipei Mayor Ko Wen-je or former legislative speaker Wang Jin-pyng to run for the top post.

Ko, an independent popular among young voters, has yet to announce if he will run for the presidency, but most opinion polls have shown he has at least 20 per cent support.

Taiwan won’t give in to Beijing as it seeks UN membership, island’s President Tsai Ing-wen says

“Han has a lot to do to explain to citizens in Kaohsiung why he broke his campaign promise [by leaving Kaohsiung and running for president],” said Liao Da-chi, a political science professor at National Sun Yat-sen University in Kaohsiung.

Vowing to turn Kaohsiung into a wealthy city, Han, who has been in office for just seven months, had promised that if he became mayor he would stay put in Kaohsiung.

“It will be extremely difficult for him to convince people in Kaohsiung and justify joining this presidential race,” Liao said, adding that Han could face censure from the city council, public criticism and even a recall motion.

A local civic group on Monday said it was seeking the endorsement of 130,000 Kaohsiung voters for the second stage of a recall motion to oust Han as mayor. If successful, there would be two more stages to remove Han from office, with the final hurdle requiring 580,000 votes – or a quarter of the electorate.

Shih Cheng-feng, a political science professor at National Dong Hwa University in Hualien, said Han needed to expand his support base beyond the mostly retired teachers and government workers, as well as military veterans upset by Tsai’s pension reform.

“I have my doubts over whether Han can appeal to relatively neutral voters, especially young people, given his mistakes in the past seven months,” Shih said, referring to criticism over his performance in council sessions and lack of familiarity with issues in the city.

Shih also said Han’s pro-Beijing stance was a problem for many young Taiwanese, who were concerned he would bow to pressure from mainland China.