Opposition parties submitted a resolution to the Diet on Tuesday to remove a senior ruling lawmaker as chairwoman of the Upper House Environment Committee because she extended a visit to China in April without their consensus, leading the committee to cancel a session.

The opposition-controlled Upper House is expected to pass the resolution by Thursday. It calls for Yoriko Kawaguchi, a Liberal Democratic Party member, to be dismissed as head of the committee. It would be the first such dismissal ever.

Kawaguchi, a former foreign minister, was in China on April 23 and 24 with Diet approval to attend an international conference. She extended her trip by one day to meet with a senior Chinese official, but this was without permission from the Diet and her absence forced the committee to cancel a session April 25.

Kawaguchi held talks with State Councilor Yang Jiechi, China’s top foreign policy official, in a rare move amid the dispute over the Senkaku Islands.

Kawaguchi met Tuesday evening with Prime Minister Shinzo Abe, head of the LDP.

“I will discuss with my party (on the course of action),” Kawaguchi told reporters. “I am truly sorry that I caused trouble.”

But she also said it was in the national interest for her to directly talk with Yang.

While opposition parties criticized Kawaguchi for disrespecting Diet rules, LDP Secretary General Shigeru Ishiba defended her, stressing at a news conference that the party took steps to gain understanding about her extended visit.

Chief Cabinet Secretary Yoshihide Suga said Kawaguchi had acted in the “national interest” by attempting to address the tension between Japan and China.