The Mayor of Taipei said on Thursday he will form a political party to run in Taiwan’s 2020 elections, a move that could complicate President Tsai Ing-wen’s re-election and shake up the political landscape amid heightened tension with China.

Taipei Mayor Ko Wen-je said he will set up the Taiwanese People’s Party in early August in a bid to run in legislative elections in January.The self-ruled island is also set to hold its presidential election in January at a time of precarious relations with China, which considers it a wayward province and has never ruled out the use of force to bring it under Beijing’s control.

Ko, who advocates closer cross-strait ties and is known for his colourful comments about Taiwan politics, said he will decide whether to run in the highly competitive presidential race by early September.“It’s not important whether I run or not. What matters is the well-being of the people.

Gou lost the presidential nomination for the China-friendly opposition Kuomintang last month but has not announced whether he will run as an independent in 2020.

A Mayor from the island’s south won the KMT’s nomination for the presidential election, issuing a direct challenge to Tsai.The Taiwan president is facing criticism over her party’s reform agenda amid rising diplomatic and military pressure from Beijing.