A deal between Taiwan's two opposition parties has collapsed over the Zhubei mayor race, and the fallout could hurt both sides in the 2026 local elections.

• KMT lawmaker Hsu Hsin-ying is accused of breaking a promise she made to TPP leader Huang Kuo-chang to step aside for his party's candidate.
• Her defense is that she never had the power to hand out the nomination in the first place, which critics call a betrayal dressed up as an excuse.
• The KMT is boxed in: its own primary winner already won, so dropping him now would enrage local supporters.
• The worry is contagion — a broken deal in one city could poison KMT–TPP cooperation nationwide, including in the legislature where the TPP holds the swing votes.
• Separately in New Taipei, KMT's Li Si-chuan leads DPP's Su Chiao-hui by about seven points in a new poll.

Outlook: Expect pressure on KMT chair Cheng Li-wun to intervene, but with Hsinchu County leaning blue, the KMT may simply gamble that voters come home anyway.