SEOUL -- Roh Moo-hyun, a former human rights lawyer and a U.S. Critic, is under fire as an apologist for North Korea as he campaigns to become South Korea's next president in Thursday's election.

The man who once signed on to a dissident call for the removal of U.S. troops from the Korean Peninsula represents the center-left camp in a tight two-horse race against conservative former judge Lee Hoi-chang, AFP reported.

Both candidates urged the North to retract its decision last week to reactivate its mothballed plutonium-producing facilities frozen under a 1994 deal with the United States.

But Roh sees only danger in the hardline policy espoused by his conservative rival Lee in dealing with the Stalinist neighbor and its suspected weapons program.

Lee calls for a halt to economic exchanges from the South to the North which earn foreign currency that he believes is being diverted to military use including Pyongyang's alleged plans to develop nuclear weapons.

His position is close to that of the United States, which has refused dialogue with the North until its dismantles its alleged nuclear programs.

Roh believes the stoppage in dialogue would rob Seoul of any leverage with the North and could precipitate war on the Korean Peninsula.

A son of poor peasants from South Korea's southeastern region, Roh chose the law as a path out of poverty but found his true voice as a politician defending the oppressed against South Korea's iron-fisted dictatorships.

"When I was struggling against hardships and difficulties in the past, I repeatedly vowed to myself that I would always stand with the poor and the underprivileged," Roh said this year.

He left school early but studied at night to become a lawyer and escape South Korea's rural poverty and privation.

His opponents have attacked his choice of wife -- the daughter of a man who was imprisoned for 18 years and died in jail under South Korea's Draconian national security laws for allegedly aiding North Korea during the 1950-53 Korean war.

Roh seemed destined for a career as a lawyer until an event more than 20 years ago changed the course of his life.

In 1981 he stumbled on a case of human rights abuse, which has become famous here as the "boolim incident", in which two dozen dissident students were arrested and tortured for almost two months for possessing banned literature.

Having seen students whose toe nails had been torn off during torture, Roh said his life underwent a transformation.

"When I saw their horrified eyes and their missing toe nails, my comfortable life as a successful lawyer came to an end," Roh said.

At great personal cost, Roh embarked on a new career as a pro-democracy advocate and human rights lawyer.

He challenged the authority of the military dictatorship of then president Chun Doo-hwan, and made headlines when he was jailed and suspended from practising law in 1987 on charges of abetting striking workers during a labor strike at Daewoo shipyard.

Following nationwide protests against the Chun dictatorship that same year, Roh decided to become a fulltime politician.

He won election to the National Assembly in 1988 as a member of the party of another pro-democracy activist, Kim Young-sam, who later became president.

Roh, then a novice lawmaker, won fame in his first year as a member of the Assembly during a parliamentary hearing on the past wrongdoings of Chun's government.

In the early 1990s he signed on to a petition calling for U.S. troops to leave Korea but has since reversed his stand, although he wants to revise the U.S.-South Korea alliance which he says is unbalanced in Washington's favor.

Though he himself is untarnished, his campaign has been damaged by corruption scandals surrounding the administration of outgoing President Kim Dae-jung, from Roh's Millennium Democratic Party.

Roh is pro-labor while Lee, a former Supreme Court judge and former prime minister who represents the opposition Grand National Party, favors more market-oriented policies.