A top business leader urged the Liberal Democratic Party on Monday to "humbly" promote economic reforms after its sweeping victory in the House of Representatives election.

"The LDP should humbly go ahead with structural reforms while refraining from becoming tyrannical after its excessive victory," Hiroshi Okuda, chairman of the Japan Business Federation (Nippon Keidanren), said.

The LDP gained 84 seats in the election, which brought its total to 296 in the 480-seat Lower House. This means the LDP and coalition partner New Komeito now command more than two-thirds of the powerful chamber.

Prime Minister Junichiro Koizumi engineered the victory by making postal privatization the main issue, but critics have cautioned that voters backed the ruling coalition in the hope that privatization of the gigantic postal system will lead to even bigger economic reforms.

Okuda indicated he expects the LDP to use the victory to accelerate structural reform. "Such a victory would be meaningless unless reforms are sped up," he said.

The landslide could prompt the party to extend Koizumi's term as LDP president, which expires in one year, but given Koizumi's nature -- as well as his latest remarks -- he may indeed quit in September next year, Okuda said.