Prime Minister Shinzo Abe plans to replace Shigeru Ishiba as the No. 2 man in the ruling Liberal Democratic Party and has sounded him out about assuming a newly created Cabinet post for defense legislation, a party source said Tuesday.

The envisioned changes would be part of Abe's Cabinet reshuffle scheduled for the first week of September, his first since taking office in December 2012. Abe, who heads the LDP, also plans to reshuffle party executives.

Ishiba, the LDP's secretary-general, is widely regarded as a potential future prime minister. He has refrained from making his stance clear on the proposed move, the LDP source said.