The official electioneering period for the country's upcoming presidential election began Monday with 15 hopefuls vying for the top elected office.

The 22-day campaign period will end one day before the May 9 election, according to the National Election Commission.

A total of 15 candidates registered to run for the election over the weekend, matching the record number of presidential candidates in a presidential election set in 2007.

They include front-runner Moon Jae-in of the liberal Democratic Party, also the single largest party in the country's unicameral parliament.

Others include Ahn Cheol-soo of the center-left People's Party, Hong Joon-pyo of the former ruling Liberty Korea Party, Rep. Yoo Seong-min of the conservative Bareun Party and Rep. Sim Sang-jeung of the progressive Justice Party.

Rep. Cho Won-jin is running on the ticket of the recently launched Saenuri Party.

One candidate is running independent while the other eight are candidates of political parties that currently hold no parliamentary seats.

The election, however, is increasingly seen as a two-way race between two front-runners -- Moon and Ahn -- who together have garnered more than 80 percent of all votes in most recent polls.

With the start of the official electioneering period, each candidate may place up to 3,400 street banners and 93,000 posters throughout the nation, promoting their runs for the presidency, and mail up to 23 million handouts to households, the election watchdog said.

They may also purchase up to 30 one-minute TV commercial spots, along with up to 70 newspaper advertisement sections each.

All such activities may cost tens of billions of won and must be paid for by the candidates or their political parties, if they have one.

The NEC has said each candidate may spend up to 50.9 billion won ($44.57 million) during their official campaign.

The election watchdog will fully refund the money, as long as they are proven legitimate and if the candidate wins more than 15 percent of all eligible votes cast in the upcoming election.

Candidates with less than 15 percent but more than 10 percent of all votes will be reimbursed 50 percent of their costs, while those with less than 10 percent will be reimbursed none. (Yonhap)