A government panel investigating pathways to Emperor Akihito's abdication will emphasize in a forthcoming interim report the merits of allowing him to step down through a one-off legal mechanism, a source said Thursday.

The panel, set up after the elderly Emperor, 83, hinted in a rare video last August that he wanted to pass the throne to Crown Prince Naruhito, is scheduled to release a report summarizing its three months of discussions on the issue on Monday.

The report will stress the difficulty of making abdication a permanent provision in Imperial succession, according to the government source.