A spat has broken out inside Taiwan's ruling and opposition camps over a local official who joined a China-hosted forum, with the government pushing back hard against a rival mayor's demands.

• Taitung County's chief, Rao Ching-ling, took part in China's "Straits Forum" through a pre-recorded video, despite a ban on officials attending.
• Taiwan's Mainland Affairs Council decided not to punish her, saying her remarks were just polite greetings and promoting farm produce, with no political content.
• Taipei Mayor Chiang Wan-an jumped in and demanded the council apologize to Rao for investigating her.
• The council's deputy chief and spokesman, Liang Wen-chieh, hit back that the whole matter is none of Chiang's business and asked if reaching from Taipei all the way to Taitung was overstepping.

Outlook: The public feud is likely to keep simmering as Taiwan argues over how tough to be on officials who engage with Beijing.