noun
party leaders' debate (in the Diet)
A formal debate held in the Japanese Diet between the leaders of political parties, typically the prime minister and opposition leaders.
今日の党首討論では、経済政策について激しい議論が交わされた。
In today's party leaders' debate, there was a heated discussion about economic policy.
党首討論は国会の重要な行事の一つだ。
The party leaders' debate is one of the important events in the Diet.
国会討論 is a broader term for any Diet debate, while 党首討論 specifically refers to the debate between party leaders.
Compound of 党首 (party leader) and 討論 (debate).