Taiwan's biggest local election battle is heating up as both major parties turn candidate registration into a show of force in New Taipei City.

• Democratic Progressive Party candidate Su Chiao-hui registers on Sept. 2; Nationalist candidate Lee Ssu-chuan follows on Sept. 4.
• Both will bring party councilors and council candidates along to project unity behind their pick.
• Lee brushed off questions about who escorts him, saying New Taipei's 4 million residents are his biggest backers.
• Sitting mayor Hou Yu-ih, term-limited and once Lee's fellow deputy mayor, promised to stand with him to the end but stopped short of confirming he will attend the registration.

Outlook: Expect the two camps to escalate the unity messaging as the campaign formally kicks off, with Hou's exact role in Lee's operation still to be announced.