TAIPEI/HONG KONG - Ever since a civil war split the two sides more than 60 years ago, China has viewed Taiwan as a renegade province that needs to be absorbed into the mainland. To that end, the legion of Taiwanese businessmen working in China is a beachhead.
In June, hundreds of those businessmen gathered in a hotel ballroom in the southern Chinese city of Shenzhen. They were there to toast the new head of a local Taiwan merchants'association.
They sipped baijiu liquor and ate seafood as a troupe performed a traditional lion dance for good luck.
An honoured guest, senior Communist Party official Li Jiafan, stood to deliver congratulations and a message.
"I urge our Taiwanese friends to continue to work hard in your fields to contribute to the realisation of the Chinese dream as soon as possible," said Li, using a nationalist slogan President Xi Jinping has popularised.
"The Chinese dream is also the dream of the people on both sides of the Taiwan Strait - our dream of reunification."
Li, who ended his speech to beating drums and loud applause, is a department chief in the Shenzhen arm of the United Front Work Department, an organ of the Communist Party's Central Committee.
Its mission: to spread China's influence by ultimately gaining control over a range of groups not affiliated with the party and that are often outside the mainland.
United Front documents reviewed by Reuters, including annual reports, instructional handbooks and internal newsletters, as well as interviews with Chinese and Taiwanese officials reveal the extent to which the agency is engaged in a concerted campaign to thwart any move toward greater independence by Taiwan and ultimately swallow up the self-ruled island of 23 million.
The United Front's 2013 annual work report for the Chinese province of Zhejiang, for instance, includes the number of Taiwanese living in the province, the number of businesses they run as well as an entry on background checks that have been conducted on the Taiwanese community in the province, an entrepreneurial hub near Shanghai.
The United Front hasn't confined itself to the mainland. It is targeting academics, students, war veterans, doctors and local leaders in Taiwan in an attempt to soften opposition to the Communist Party and ultimately build support for unification. The 2013 work report, reviewed by Reuters, includes details of a programme to bring Taiwanese students and military veterans on visits to the mainland.
Through the United Front and other Chinese state bodies like the Taiwan Affairs Office, which is responsible for implementing policies toward Taiwan on issues including trade and transport,
Beijing has also tried to influence politics on the island, in part by helping mobilise Taiwanese businessmen on the mainland.
Many of them are heading back home this weekend to vote in mayoral elections that are being viewed as a barometer of support for Taiwan's ruling Nationalist Party, or Kuomintang (KMT), which favours closer ties with China than does the pro-independence Democratic Progressive Party (DPP).
A large number of those businessmen, who a senior KMT source said will largely vote for the party, will be flying on deeply discounted airfares being offered by Chinese and Taiwanese airline companies.