Taiwan’s ruling Democratic Progressive Party has warned mayors belonging to the Beijing-friendly Kuomintang party who were planning visits to China that they must be careful what they say or if they sign any deals on cross-Strait ties.

The backdrop to the stern warning was that the KMT’s Han Kuo-yu, who singlehandedly smashed the DPP’s stronghold in Kaohsiung – the island’s second-largest city – and clinched victory in the city’s mayoral election in November, will embark on a much-hyped week-long visit to Hong Kong, Macau, Shenzhen and Xiamen this month.

Taiwanese Premier Su Tseng-chang said on Wednesday that mayors must be wary of any political framework Beijing might try to impose, adding that handling relations with China was the turf of the central government and local mayors should not overstep their authority.

“Do not be hemmed in by political frameworks imposed by a totalitarian Chinese government that has not given up annexing Taiwan by force,” Su was quoted as saying by the island’s Central News Agency.

The island’s Mainland Affairs Council was still vetting Han’s application for a permit to visit the mainland and some DPP lawmakers had proposed national-security amendments to subject regional officials to treason charges should they visit and collude with China, according to Taiwanese papers.

Han previously promised that his trip would not be political but intended to explore opportunities to further economic, trade and tourism exchanges across the Taiwan Strait, and he would not meet high-ranking Chinese officials.

Han said he aimed to compare notes on trade and economic development with Hong Kong officials and sell Kaohsiung’s investment opportunities to Hong Kong’s business community. Meanwhile, the Hong Kong government said details of Han’s visit were still being worked out, when asked if the city’s top leader would meet with him.

Taiwan’s former president Ma Ying-jeou was denied permission to visit Hong Kong, his birthplace, soon after the end of his tenure in 2016. Photo: Handout

Taiwan’s former president Ma Ying-jeou, of the KMT, had his travel permit rejected by his DPP successor Tsai Ing-wen when he planned to visit Hong Kong, his birthplace, merely one month after the end of his tenure in June 2016.

Tsai insisted back then that Ma was subject to immigration control for national-security reasons, having only been out of office for one month, while the restriction would typically last for three years. She added that allowing Ma’s trip would be detrimental to Taiwan’s interests.

But this time Han is unlikely to face any such travails as Tsai, already a lame duck after her party’s election drubbing in November, could be lending her critics more ammunition if she moves to block city-to-city-level exchanges.

Han, now riding a popularity wave after showing his skills at canvassing for votes, was seen as a potential contender for the island’s top office in the 2020 presidential election to crush the DPP’s hopes of continuing its rule.