TAIPEI - About 80 percent of 18 million eligible voters are expected to turn up at 14,806 polling stations to cast their ballots Saturday in the island's fifth leadership election since 1996, a Taiwan official in charge of election affairs said Friday.

Results for the leadership and "legislative" election, held every four years, will be announced before 10 pm Saturday, Chang Po-ya, chairwoman of the island's election commission, said at a press conference.

The commission held a rehearsal for the computer-facilitated ballot-counting ahead of the press conference.

In a three-way race, incumbent Taiwan leader and ruling Kuomintang (KMT) chairman Ma Ying-jeou, who is seeking a second term, and his running mate Wu Den-yih, incumbent chief of the island's executive authority, are competing for Taiwan's next leadership role with major opposition Democratic Progressive Party (DPP) chairwoman Tsai Ing-wen and her running mate Su Jia-chyuan, and the minority People First Party (PFP) chairman James Soong and his running mate Lin Ruey-shiung.

The order on the ballot sheet is: Tsai and Su, Ma and Wu, and Soong and Lin, according to lot drawing.

Polls will open at 8 am and close at 4 pm Chang said, adding that more than 198,000 electoral workers will serve at polling stations across the island.

It is the first time for leadership and "legislative" elections to be held simultaneously in Taiwan to save costs.

For the "legislative" poll, 283 candidates are running for 79 directly elected regional and aboriginal seats, and 127 candidates from 11 parties are vying for 34 at-large seats. Taiwan's "legislature" has 113 seats.

Each eligible voter will cast two ballots in the "legislative" elections -- one for a candidate representing the voter's district and the other for a political party to decide how many at-large seats each party can obtain, Chang said.

As Friday was the final day of campaigning, Chang said all stumping activities must end before 10 pm Friday. She also called on the electorate to vote and abide by voting rules, such as cell phones forbidden from polling compartments.