More than 200,000 Taiwanese businessmen and their relatives currently based in China are expected to return to the island to vote in the presidential elections, a business group estimated Tuesday.

At least 3,000 based in Beijing, and the remainder from around China, plan to return for Saturday's polls keen to have a say in future ties with China, said Lin Ching-fa, head of a leading businessmen's association in Beijing.

"This time the election is very tight and more businessmen than previously intend to come back to vote to protect their investment rights," Lin said.

About 148,000 mainland-based businessmen came back to vote in the 2008 election, when Ma Ying-jeou, the candidate of the Beijing-friendly Kuomintang party, won a landslide victory.

Taiwan's two leading carriers China Airlines and EVA Airways said cross-strait flights this week are nearly fully booked and that they have operated additional flights to meet the demand.

Tensions between Taiwan and China mounted during the 2000-2008 term of the former government of the Democratic Progressive Party (DPP), which launched policies promoting the island's independence.

Ties have improved markedly since Ma took office, with measures to boost trade and tourism, culminating with the signing of a major trade pact in 2010.

"The businesspeople don't want the situation to deteriorate to what it was before 2008," said Lin.

Ma, who is seeking a second and final four-year term, is locked in a neck-and-neck race against the DPP's Tsai Ing-wen.

Lin estimated that 80 percent of the mainland-based businessmen are rooting for a Ma victory, as they are concerned about the consequences if the DPP were to win.

Peng Ming-Min, a former presidential adviser to the president in the DPP government, claimed that China has been "meddling in the election" by encouraging the businessmen to return to vote.

"This is an open secret that the Chinese government has asked Taiwanese people doing business in China to come back to vote for the Kuomintang candidate," he said.