Former President Moon Jae-in's memoirs are displayed at Kyobo Bookstore in Gwanghwamun, Seoul, Sunday. Yonhap

Former President Moon Jae-in has triggered intense debate with his recently published memoir, reigniting controversy surrounding his wife's visit to India during his term.

It has sparked a fresh call from the ruling People Power Party (PPP), which was the opposition party at the time, to investigate former first lady Kim Jung-sook. The party claims that the visit was aimed at fulfilling her wish to visit the Taj Mahal on taxpayer money, despite Moon's explanation that the Indian government invited her.

The main opposition Democratic Party of Korea (DPK), which was the ruling party at the time, is baffled by the resurfacing of the issue. Additionally, the mainstream of the DPK, a faction loyal to its Chairman Lee Jae-myung, questions the timing of the memoir, particularly as unity within a faction supporting Moon has been growing ahead of Thursday's memorial event for former President Roh Moo-hyun, Moon's longtime friend.

The memoir, titled "From the Periphery to the Center," published Saturday, contains Moon's reflections on major issues during his presidency from May 2017 to May 2022.

Creating controversy was Moon's description of his wife's 2018 visit to India using the presidential jet, which drew criticism from conservatives at the time. They argued that the first lady's trip amounted to a junket financed by taxpayer money.

"Indian Prime Minister Narendra Modi invited me to return to India for the opening of the Heo Hwang-ok Memorial Park, but it was difficult for me to visit India again," Moon wrote.

"So I declined, and India then asked me to send my wife instead … The reason I elaborate on this is that there are people who maliciously distort (the facts) as if my wife went on a junket using taxpayer money."

Moon described the visit as "the first standalone diplomacy by a first lady." It was the first time for the former president to speak about the controversy, which has been a target of criticism from the conservatives for years.

Then-first lady Kim Jung-sook, left, walks with Indian Prime Minister Narendra Modi at his residence in New Delhi, Nov. 5, 2018. Yonhap

The Ministry of Foreign Affairs said, however, India first extended an invitation to then-Foreign Minister Kang Kyung-wha.

In a statement released on Monday, the ministry explained that it declined the invitation extended to Kang due to her other commitments. Subsequently, India extended an invitation to then-Culture Minister Do Jong-hwan. During the communication regarding Do's trip, the ministry informed India that the first lady, Kim Jung-sook, might accompany the delegation, prompting India to send an invitation to her.

The PPP is raising its voice against Moon's account of Kim's visit to India, calling for an investigation into the trip.

"Kim's trip was not an example of standalone diplomacy, but a standalone junket," PPP Rep. Yoon Sang-hyun said during a radio interview with KBS. "Her visit to Taj Mahal seems to be the subject of a special counsel probe."

Then-President Moon Jae-in talks with North Korean leader Kim Jong-un in Panmunjeom during their summit, April 27, 2018. Yonhap

Moon's comments on the summit between himself and North Korean leader Kim Jong-un, as well as former U.S. President Donald Trump and Kim, also stirred considerable debate.

Recalling his talks with Kim during their summit in April 2018, Moon said, "Kim reiterated that he has no intention to use nuclear weapons."

Moon also noted that the second U.S.-North Korea summit, held in February 2019, was delayed more than expected because then-U.S. Secretary of State Mike Pompeo "demanded a list detailing their nuclear-related facilities, capabilities, and weapons," ultimately leading to the summit ending without any deal.

In response, Unification Minister Kim Yung-ho told reporters on Monday that ignoring North Korea's missile and nuclear capabilities and focusing solely on its intentions would lead to making incorrect judgments about the situation.

Regarding the PPP and the government's offensives, members of the pro-Moon faction within the DPK are expressing strong opposition.

Moon's former spokesperson, Rep. Ko Min-jung, called the offensive "a smear campaign not even worth responding to."

However, the mainstream of the DPK is not actively responding to the ruling bloc's offensives. Some members say the memoir "unnecessarily offered" a chance for the ruling bloc to mount offensives.

Amid mixed responses within the party, its pro-Moon faction is asserting its influence ahead of a memorial ceremony for Roh, the deceased former president, who was a friend and political mentor to Moon.

The ceremony will take place in Roh's hometown of Gimhae, South Gyeongsang Province, on Thursday. Not only Moon, but also a slew of pro-Moon faction members — including former South Gyeongsang Province Gov. Kim Kyoung-soo, a protégé of Moon who recently arrived here from the United Kingdom — are expected to attend the ceremony.