Rep. David Wu (D-Ore.) announced Tuesday he will resign from Congress following accusations he had unwanted sexual contact with a teenage girl.

"I cannot care for my family the way I wish while serving in Congress and fighting these very serious allegations," Wu said in a statement.

Wu claims the incident with the daughter of a longtime friend and donor--who is now 18 years old--was consensual, and said he will continue to serve until the resolution of the debt ceiling battle.

Wu for months faced intense pressure back home to resign following reports of his erratic behavior. Prior to today's announcement, he tried to deflect such pressure by stressing that he was undergoing mental health treatment. On Friday, Wu's problems deepened when The Oregonian reported on the allegations over the unwanted sexual encounter.

House Democrats on Sunday called for an ethics investigation into the incident, increasing the public pressure on the seven term congressman to leave office. Wu at first indicated he would simply retire in 2012, and would not resign.

Wu disclosed in July 2010 that he had stopped drinking. He was legally separated from his wife the following month. This past February, the congressman admitted to receiving mental health treatment following reports of his bizarre behavior.

Due to Wu's perceived vulnerability, a competitive 2012 race had already been taking shape in his 1st District. State labor commissioner Brad Avakian began campaigning for the seat in April and has been joined by state Rep. Brad Witt for the Democratic nomination. The seat overall leans Democratic.