Ahn Cheol-soo, a potential dark-horse candidate for Seoul mayor, is far ahead of other possible contenders from both the ruling and opposition parties, multiple surveys showed Monday. Ahn, a former doctor, rose to fame in the 1990s after establishing Ahnlab Inc., one of South Korea\'s best-known anti-virus software firms. He has been reported to be considering a run for mayor as an independent candidate. On Friday he strongly hinted that he may run in October\'s by-election, saying that he has distanced himself from politics so far because one lawmaker cannot make any difference, but he believes \"there are lots of things a mayor can change.\" Ahn, now dean of the Graduate School of Convergence Science and Technology at Seoul National University, is widely popular, especially among young Koreans, due in part to his clean image. His sudden emergence has put major political parties on edge. Attesting to his popularity, a series of surveys showed Monday that the 50-year-old Ahn has a commanding lead over other possible candidates from the ruling Grand National Party (GNP) and the main opposition Democratic Party (DP). A JoongAng Ilbo survey, conducted by Gallup Korea on Saturday, showed that Ahn has 39.5 percent support among 1,006 Seoul citizens. Trailing him were two female politicians -- Rep. Na Kyung-won of the GNP with 13 percent and the nation\'s first female prime minister, Han Myeong-sook of the DP, with 10.9 percent. Though Ahn has not yet officially announced his candidacy, his close aides say if he chooses to run he would do so as an independent with no party affiliation, in line with his efforts to keep a distance from the unpopular political establishment. Another survey, commissioned by the daily Kookmin Ilbo and conducted by GH Korea on 500 Seoul residents over the weekend, also showed that Ahn has 36.7 percent support, far ahead of Na with 17.3 percent and Han with 12.8 percent. On Monday, political parties showed mixed responses to Ahn\'s rise. \"People usually pay attention to fresh figures not affiliated with parties and give them credit,\" GNP leader Hong Joon-pyo said in a radio interview. \"We see (the poll) as a popularity vote at this point, which could not directly affect approval ratings.\" Na, the GNP\'s front runner, said politicians should take Ahn\'s popularity as a wakeup call. \"We should consider (Ahn\'s rating) as an order from the people to end the old politics and change, while considering his existence as a vaccine (for the party),\" Na said in a senior party meeting, referring to the anti-virus software expert. DP leader Sohn Hak-kyu invited Ahn to join his party to steer the liberal coalition to victory. \"Those who oppose the GNP should be in the same boat,\" Sohn said in a party meeting, urging Ahn to join the party convention to compete with other candidates in the liberal bloc. Ahn, an open critic of large conglomerates over unfair business practices, had earlier said that he neither wants to join the GNP nor considers the main opposition DP as a real alternative to the conservative ruling party. The Seoul mayoralty was vacated late last month when conservative mayor Oh Se-hoon stepped down after failing to block an opposition-led free school lunch program in the city\'s first-ever referendum. By law, the Seoul mayoral election is set for Oct. 26. The October by-election has drawn close attention as it is widely seen as a litmus test of public sentiment ahead of parliamentary elections next April and the presidential race in December 2012.