The National Assembly will convene its disciplinary committee Thursday to review a sitting lawmaker -- formerly affiliated with the ruling party -- accused of sexual assault.

Rep. Sim Hag-bong, who left the ruling Saenuri Party earlier this month, is being investigated by prosecutors on the suspicion of sexually assaulting a woman in her 40s at a hotel in Daegu, a major city in North Gyeongsang Province, on July 13.

The National Assembly's Ethics Committee will hold its first meeting later on Thursday to begin the process of taking disciplinary action on the embattled lawmaker.

The committee's meeting comes after a group of 25 female lawmakers from the main opposition New Politics Alliance for Democracy filed a motion, calling for Sim to be punished.

Sim left the ruling party earlier on Aug. 3, noting that he does not want to place any burden on it.

The Saenuri Party accepted Sim's letter of defection. His defection lowered the number of seats held by the ruling party in the 298-member parliament to 159. (Yonhap)