Lawmaker Kishiro Nakamura, a former construction minister, is preparing to file an objection over Thursday's Supreme Court rejection of his appeal against a bribery conviction, sources said Friday.

Nakamura, a former Liberal Democratic Party lawmaker, is expected to submit the objection to the top court by Monday. It is unlikely the court will reverse its decision, however. The court is expected to throw his objection out within seven to 10 days, thereby finalizing his sentence of 18 months in prison and 10 million yen fine.

If the ruling becomes final, Nakamura, 53, will lose his seat in the House of Representatives and be sent to prison.

The top court dismissed his appeal of a 2001 Tokyo High Court ruling, which found Nakamura guilty of taking 10 million yen in bribes from Shinji Kiyoyama, a former vice president of major general contractor Kajima Corp. in 1992, in return for a favor.

Nakamura was a deputy chairman of the LDP's panel on antimonopoly policy at the time. He later went on to serve as construction minister.

Kiyoyama, 76, does not plan to file an objection over the top court ruling. He was sentenced to a suspended 18-month prison term. The suspension was for four years.