Justice Minister Han Dong-hoon sits at the National Assembly's Legislation and Judiciary Committee meeting in Yeouido, Seoul, Thursday. Yonhap

Justice Minister Han Dong-hoon and main opposition Democratic Party of Korea (DPK) Chairman Lee Jae-myung are engaged in a closely contested race in a poll gauging public opinions on who should be the next president, fueling speculation that Han may enter politics in the near future.

In a Gallup Korea poll released on Friday, 19 percent of respondents selected Lee, who competed against President Yoon Suk Yeol in last year's presidential election, as their preferred next president, with Han closely following at 16 percent.

This marks the first case of Han, an outspoken former prosecutor widely seen as a close aide of President Yoon, competing with Lee within the survey's margin of error, which is plus-minus 3.1 percentage points.

Despite his defeat in the presidential election in March last year, the liberal main opposition leader has been maintaining a solid lead over other presidential hopefuls, such as conservative Daegu Mayor Hong Joon-pyo and former DPK Chairman Lee Nak-yon.

Han, who first made it into the monthly Gallup survey in June with 4 percent, has been enjoying a stable upward trajectory. He reached a personal best of 16 percent in this month's survey, up 3 percentage points from a month earlier.

Gallup Korea attributed Han's rise to recent speculations whether he will run in the general elections next April.

Han is gaining keen political attention ahead of the general elections as a notable figure of the ruling People Power Party (PPP), and he is also expanding contact with the general public.

During a visit last month to Daegu, a conservative stronghold, Han said the general elections are very important for the people's livelihood. On Wednesday, the justice minister attended a PPP lawmakers' meeting at the National Assembly and talked about the importance of immigration policy.

Though Han has yet to show any intention to enter politics, pundits are already seeing him as the linchpin of the conservative bloc, given his unwavering personality and public popularity.

Meanwhile, the survey showed that 51 percent of respondents said opposition party candidates should gain more Assembly seats during the general elections to contain the Yoon administration. This surpassed 35 percent who said ruling party candidates should outnumber opposition to support the government.

Yoon's job approval rating remained flat at 32 percent from a week earlier.

The poll surveyed 1,000 adults from Dec. 5 to 7. Further details are available on the National Election Survey Deliberation Commission's website.