Veteran lawmaker Masahiko Komura, vice president of the ruling Liberal Democratic Party, has decided not to run in the Lower House election next month after deciding it will be too physically taxing, a source close to the matter said Monday.

The 75-year-old lawyer-turned-lawmaker, who served as foreign, defense and justice ministers and held other key Cabinet posts, has already told Prime Minister Shinzo Abe, who doubles as LDP chief, of his plans, the source said.

Komura was first elected to the House of Representatives in 1980 from a constituency in Yamaguchi Prefecture. Since Abe returned to power in 2012, Komura, as LDP vice president, has played a key role in enacting laws allowing Japan to engage in collective self-defense, or defending an ally under armed attack, and a special law to permit the abdication of Emperor Akihito.

He has also been a key player in the LDP's discussions on amending the war-renouncing Constitution.

Abe said he will dissolve the House of Representatives for a snap election when it convenes on Thursday.