Taiwan's ruling DPP is lining up its biggest names behind its city mayor candidates, a sign the party is going all-in on unity for the year-end local elections.

• Registration for Taiwan's local elections runs through early September, and the DPP's main candidates in Taipei, New Taipei, Taoyuan, Taichung and Kaohsiung are all signing up on the same day.
• Former president Tsai Ing-wen is expected to accompany Taipei candidate Puma Shen to register, though the campaign says the timing is still being worked out.
• Tsai already chairs three DPP campaign teams, and adding Taipei would put her weight behind the party's toughest race against incumbent mayor Chiang Wan-an.
• In New Taipei, a new poll shows DPP candidate Su Chiao-hui edging ahead of the KMT's Lee Si-chuan for the first time, but the gap is within the margin of error.
• A separate scandal is hanging over Taipei city hall: a 10-year-old girl reported as a suspected abuse victim went months without being placed in care, and both parties are trading blame over who designed the failed system.

Outlook: Expect the candidate line-ups to be locked in within days, with Taipei and New Taipei shaping up as the closest and most closely watched races.