The 5 percent consumption should be hiked to 10 percent "in two stages," with the first raise coming in April 2009, Finance Minister Sadakazu Tanigaki suggested Friday.

Tanigaki, who announced his candidacy for the Liberal Democratic Party presidential race the previous day, declined comment on the scale of the first hike, only saying he needs to study the issue more.

Tanigaki said Thursday he aims to double the tax to 10 percent sometime in the next decade in order to restore Japan's financial health. The tax hike is one of the three policy proposals he has made in the race to choose the successor of Prime Minister Junichiro Koizumi.

Two other proposals are to improve relations with China and South Korea and revitalize regional economies.

Koizumi is set to step down as prime minister in September, when his term as LDP president expires.

Separately, Tanigaki said Friday he will attend a meeting in Singapore of the Group of Seven nations, to be held just before the Sept. 20 election to chose the LDP president — a job that carries with it the prime ministership, given the LDP's dominance in the House of Representatives.

Japan will chair the Singapore gathering of G7 finance ministers and central bank chiefs. The meeting is expected to focus on reforms of the International Monetary Fund and macroeconomic issues.

Other prime minister hopefuls include Chief Cabinet Secretary Shinzo Abe and Foreign Minister Taro Aso.