The Diet is expected to approve the government's nominees for Bank of Japan governor and its two deputy governor posts, with the largest opposition party set to give the nod for Asian Development Bank President Haruhiko Kuroda to head the central bank, lawmakers said Tuesday.

Besides Kuroda, the Democratic Party of Japan plans to accept the nomination of BOJ Executive Director Hiroshi Nakaso for one of the deputy governor posts but may reject the other nominee, Kikuo Iwata, a Gakushuin University professor who advocates bolder monetary easing to achieve the central bank's 2 percent inflation target.

All three nominations, however, are expected to secure Diet approval, given that smaller opposition parties are planning to vote for Iwata.