Prime Minister Shinzo Abe on Tuesday reiterated the need for explicitly defining the status of Japan’s Self-Defense Forces under his plan to revise the pacifist Constitution by 2020.

“Unfortunately many constitutional scholars say the SDF is unconstitutional (per the war-renouncing Article 9),” Abe told the Upper House Budget Committee. “I believe it’s the responsibility of our generation to change such a situation.”

The remarks were among only a handful he would make on his desire to amend the charter during a face-off Tuesday with Democratic Party opposition leader Renho, who goes only by her first name.

A week after making a surprise announcement about his ambition to revise the Constitution by 2020, Abe has remained doggedly tight-lipped about how exactly he wants to go about changing the supreme law of the land, which was drafted by the Allied forces after the nation’s defeat in World War II.

On Wednesday last week, Abe announced in a video message shown at a Tokyo convention celebrating the 70th anniversary of the enforcement of the charter that his desire was for a revised Constitution to take effect in 2020 to coincide with the Tokyo Olympics. He stressed at the time a need to explicitly define the role of the SDF.

On the same day, the conservative Yomiuri Shimbun published an exclusive interview with the prime minister detailing his plans.

But contrasting sharply with his willingness to expound on the matter last week, Abe, who was summoned to the Diet this week, has stayed mum on the issue, repeatedly asserting further details should be debated among political parties at a Diet panel specifically tasked with revising the Constitution.

“I’m summoned to speak here as prime minister, not as president of the (ruling) Liberal Democratic Party,” Abe repeatedly told the Upper House Budget Committee on Tuesday.

The rationale is that his capacity as prime minister absolves him of any obligation to elaborate before the Diet about how the LDP wishes to change the charter. In an apparent bid to justify the discrepancies in his willingness to address the issue, Abe said his comments in the video message and the interview with the Yomiuri were made as president of the LDP.

Renho, known for her fiery rhetoric, charged that Abe’s refusal to speak at the Diet amounts to an “extreme double standard” that shows “disregard” for the legislature.

Such apparent disrespect for Diet procedures, she said, was also evident in Abe’s suggestion at a Lower House committee on Monday that opposition lawmakers should just peruse his Yomiuri interview if they are so keen to know more about how he wishes to amend the Constitution as the head of the LDP. She demanded that the remark be retracted.