South Korea front-runner goes for presidency

SEOUL, May 10 (Reuters) The front-runner to be South Korea's next president officially declared his candidacy today, just as deepening internal bickering threatened to break up his conservative party.

Former Seoul Mayor Lee Myung-bak is in the midst of a bitter fight with his chief opponent for the Grand National Party's (GNP) nomination, Park Geun-hye, over rules for primaries ahead of the Dec. 19 presidential vote.

''I want to be the national chief executive officer, not the country's most powerful person,'' said 65-year-old Lee, who has consistently led opinion polls with about 40 percent support.

''I want to be a president who does the job right, not a president who says the right things,'' he told a news conference.

Lee, one-time top manager at the giant Hyundai conglomerate who moved into politics in the 1990s, pledged to boost the already powerful South Korean economy and double per-capita income to 40,000 dollars a year.

His formal bid came a day after the chairman of the opposition GNP proposed new rules giving greater weight to public opinion polls in picking the party's candidate and which many see as favouring Lee.

His opponent -- former party leader and daughter of assassinated former dictator Park Chung-hee -- has refused to accept the changes, calling them undemocratic. She trails Lee in opinion polls with about 20 percent support.

The party has been struggling to find an acceptable formula for its primary that balances votes from the public, party members and MPs.

Lee's camp wants greater weight given to the general public, while Park is demanding more say for the rank-and-file members.

Some Park supporters say she may even pull out and run as an independent.

''That won't likely happen,'' said political analyst Yu Chang-seon. ''She knows full well that that'll mean the end of her political life.'' GNP leader Kang Jae-sup has said his proposal is not up for discussion.

A popular politician who led successive election victories during two years as party leader, Park's main support is seen as limited to her home region in the southeast of the country and central provinces.

Lee, partly due to his popular tenure as the capital's mayor, appears to have a broader political base beyond the regional preferences that have long dominated South Korean politics.

The potential split within the GNP follows what appears to be the imminent disintegration of the left-leaning and increasingly unpopular Uri party, which helped bring outgoing President Roh Moo-hyun to power.

Its main candidate, Chung Dong-young, has already fallen out with Roh and trails far behind in opinion polls.

The only other candidate currently seen with much of a chance in December's poll is centrist Sohn Hak-kyu, who quit the GNP in April.

He is a fairly distant third behind both Lee and Park.

Reuters RJ RS1109