A Liberal Democratic Party lawmaker is in hot water over a recent tweet that branded students protesting against the Abe administration's security legislation as "self-centered" and "extremely selfish."

Takaya Muto, 36, said on Twitter last week that members of Students Emergency Action for Liberal Democracy (SEALDs) are making a mistake by saying, "We never want to go to war."

The ruling party lawmaker said such a claim is based on a "self-centered and extremely selfish thought." He also lamented the nation's postwar education, which he said "allowed people to foster self-centered individualism."

SEALDs is credited with organizing heated youth protests outside the prime minister's office against the security legislation.

On Monday, opposition parties blasted Muto, as did some of his fellow members of the ruling camp.

Muto's tweet was an attempt to trivialize opposition to the security legislation as mere personal likes and dislikes, said Yukio Edano, secretary-general of the main opposition Democratic Party of Japan.

Muto "doesn't understand the essence of the problem at all," he said.

Edano added that the DPJ will pursue the matter until Muto takes responsibility for his remark.

Mito Kakizawa, secretary-general of Ishin no To (Japan Innovation Party), also criticized Muto, saying voters "need to check what each politician is saying and then cast their ballot."

Even Muto's boss, LDP Secretary-General Sadakazu Tanigaki, told a news conference that Muto needs to offer a more substantive explanation of his remark.