The head of South Korea's ruling Uri Party has resigned after parliament failed to pass several pieces of reform legislation by the end of 2004.

Uri Party Chairman Lee Bu-young and members of the party's standing central committee stepped down Monday citing the failure of his attempts to scrap the National Security Law.

The Uri Party vowed to push through a bill repealing the law last year, but the opposition Grand National Party blocked the legislation, saying North Korea still poses a threat to national security.

The impasse over the security legislation threatened passage of the country's budget and a one-year extension of its troop deployment in Iraq.

The Uri Party leadership plans to hold a meeting this week to pick an interim leader who will serve until a party convention in April.

Some information for this report provided by Reuters and AP.