South Korea's presidential race has officially opened, with two candidates espousing very different policies running neck and neck.

Five contenders registered their candidacy on Wednesday, but two are leading the polls - the conservative Grand National Party's Lee Hoi-chang, who supports a hard line on North Korea, and Roh Moo-hyun, a former human rights lawyer who is standing for the ruling Millennium Democratic Party.

Lee Hoi-chang has stood for president before

Mr Lee had been consistently leading the polls until Chung Mong-joon, South Korea's millionaire football chief, agreed to narrow the field by stepping down on Monday, following a head-to-head televised debate between him and Mr Roh.

In the final opinion polls allowed before the 19 December election, two surveys suggested Mr Roh had edged ahead of Mr Lee.

A Joongang Ilbo daily gave Mr Roh a 43% to 35% margin over Mr Lee, while SBS-TB had Mr Roh leading Mr Lee 46% to 39%.

North Korea

Key election issues include the economy, clean government, and policies towards North Korea.

South Korea's current "sunshine policy" of engagement with the North has been put under severe strain by Pyongyang's alleged admission that it has a nuclear weapons programme.

Mr Roh, 56, supports the continuation of exchanges with the North, despite such revelations, whereas Mr Lee has called for financial aid and economic exchanges to the North to be halted until its alleged nuclear programme is dismantled.

However Mr Lee did say on Wednesday that he hoped to hold talks with North Korean leader Kim Jong-il if elected president.

"I would hold an inter-Korean summit to settle the nuclear issue, open a road to peace and let people live safely," said Mr Lee in a statement.

North Korea, however, has consistently demonised Mr Lee in its official media, recently referring to him as an "anti-reunification element, pro-US sycophantic traitor and vicious warmonger".

Different backgrounds

Mr Lee, 67, stood for the last presidential election in South Korea in 1997, finishing a close second to Kim Dae-jung, who under South Korea's constitution must now stand down.

Mr Lee, a civil servant, and a Supreme Court judge before he entered politics, also served as prime minister under the previous government.

Mr Roh is also a former lawyer but, born to peasant farmers, he is seen as a champion of the under-privileged, whereas Mr Lee is viewed as pro-big business.

Analysts believe next month's presidential election is likely to be one of the closest in South Korea's history.