A five-term lawmaker of the ruling Saenuri Party declared his bid to run for governor of Gyeonggi Province on Wednesday, the latest in a series of big-name politicians to join what are expected to be tight races in the June local elections.

Rep. Nam Kyung-pil made his governorship bid official during a party meeting. His bid shows the ruling party is mobilizing all resources to win the upcoming elections that are seen as a midterm confidence vote for the government of President Park Geun-hye.

Nam, 49, who was elected to parliament five times in a district in Suwon, the capital of Gyeonggi Province, has been under pressure to run for governor as the party saw its chances in the race growing shaky with a series of popular opposition politicians declaring their bids for the job.

Nam had originally thought of running for the party's floor leader.

On Tuesday, Kim Sang-gon, Gyeonggi's education chief, also announced his bid for the governorship. Other opposition hopefuls include Reps. Kim Jin-pyo and Won Hye-young of the main opposition Democratic Party. Incumbent Gov. Kim Moon-soo has said he won't seek re-election as he eyes presidency.

The Gyeonggi governorship is considered one of the biggest races, along with Seoul's mayorship, in the June 4 elections that are aimed at selecting governors, mayors, heads of smaller municipalities and members of local legislatures, as well as provincial education chiefs.

Those expected to run for Seoul mayor include Rep. Chung Mong-joon of the ruling party, who had served as a vice chairman of the football's world governing body FIFA, and former Prime Minister Kim Hwang-sik, who served under former President Lee Myung-bak.

Current Seoul Mayor Park Won-soon of the main opposition DP is running for a second term.

On Tuesday, the home affairs minister, Yoo Jeong-bok, also announced his plan to run for mayor of Incheon, his hometown. Yoo was to formally declare the mayorship bid in a press conference on Wednesday.

Public office holders must resign by Thursday to run in the upcoming elections. (Yonhap)