Fukuda, the 71-year-old son of a prime minister from the 1970s and a former right-hand man to two premiers, won 63 per cent of the vote among Liberal Democratic Party (LDP) lawmakers and delegates, beating his lone rival, former foreign minister Taro Aso.

The win essentially guarantees Fukuda’s election as outgoing Prime Minister Shinzo Abe’s successor in Parliament on Tuesday because of the LDP’s vast majority in the Lower House, the more powerful of the two chambers that elects the premier. Fukuda vowed on Sunday to rebuild the popularity of his party, which has suffered a year of scandals and policy missteps by outgoing Abe, who has been hospitalised since announcing on September 12 that he would resign.

Fukuda’s key policies include engaging North Korea diplomatically, pushing for extension of Japan’s naval mission in support of US-led forces in Afghanistan, and giving aid to rural regions left behind by the economic recovery.

“We need to show our intention to continue the mission as a message to the international society,” Fukuda said of the Afghan mission, which the Opposition has vowed to defeat in Parliament. “If this drags on too long we might send a wrong message to the world as if we were not committed to making that contribution.”