The presidential office said Monday it will not respond to an opposition-led parliamentary hearing addressing an online petition for President Yoon Suk Yeol's impeachment.The parliamentary legislation and judiciary committee voted last week to hold two hearings -- on Friday and on July 26 -- to deal with the petition, posted online on June 20, that calls for the National Assembly to propose an impeachment motion against Yoon over various allegations, including first lady Kim Keon Hee's acceptance of a luxury handbag in 2022."We cannot respond to an unconstitutional and unlawful impeachment hearing," a senior presidential official told Yonhap News Agency.The first lady and her mother have been chosen as witnesses for the hearings, which the ruling People Power Party (PPP) has dismissed as "invalid."PPP lawmakers boycotted the committee vote last week that approved the plan for the hearings.Source: Yonhap News Agency