Prime Minister Shinzo Abe's surprise declaration last week that he wants to revise the pacifist Constitution by 2020 has ignited discord within his ruling Liberal Democratic Party, with some of its most influential lawmakers openly slamming his plan.

Veteran Shigeru Ishiba, who narrowly lost the party's 2012 leadership election to Abe, said Friday that the statement — released on the 70th anniversary of the charter's enforcement last week — shouldn't override the LDP's previous debates on the matter. In 2012, the LDP unveiled its own draft charter as a potential alternative to the current version, which has remained unchanged for the last 70 years.

In a video message shown at a gathering celebrating the milestone anniversary of the charter, Abe proposed mentioning the Self-Defense Forces in war-renouncing Article 9 to legitimize its status. Any new mention of the SDF can coexist with that pivotal clause and does not necessitate a revision to its phraseology, he said.