As the Taipei mayoral race enters its final stretch, the anxiety within the green camp centres on offensives built on rumour and smears — clearly bad news for Puma Shen's campaign.

• Robert Tsao likens the methods of the Chinese Communist Party and the KMT to a "shameless machine": a relentless stream of fabricated rumours, quotes taken out of context and truth turned on its head, at very low cost but with outsized effect. In Taiwan only defamation law can address it, and even a conviction carries little sting.

• He cites Chen Shih-chung, who was smeared and lost the last Taipei mayoral race, and last year's mass recall campaign, which left Lai Ching-te's image badly battered.

• This wave of attacks targets Puma Shen's position on drugs. Lo Chih-chiang took a paper Shen wrote more than a decade ago out of context and claimed he wanted to deliver drugs into every household; KMT members of the Taipei City Council followed up with a press conference of their own.

• Tsao suggests assigning numbers to the people involved and teaching the public how to identify them. His greatest worry is that neutral voters, once deceived, will simply not turn out to vote.

• The green camp came under pressure on two fronts the same day: Overseas Community Affairs Council Minister Hsu Chia-ching resigned over a controversy involving family members accompanying her on an official trip, while Taipei prosecutors uncovered that a Hong Kong resident had paid a large sum to commission a Taiwanese private investigation firm to keep Puma Shen under round-the-clock surveillance. Four people have been indicted.

Outlook: The drug issue is only the first wave. With less than two months left in the campaign, the attacks and counterattacks will only intensify.