Both the ruling and opposition blocs were divided Sunday over an earlier proposal by the Democratic Party of Japan to lower the minimum income-tax threshold to increase tax revenue.

On a round-table discussion program aired by TV Asahi, Shizuka Kamei, top policymaker of the ruling Liberal Democratic Party, said, "The DPJ is seeking to raise the tax burden for young people with less income and for those working in agricultural and fishing communities."

His counterparts from five other political parties also took part in the discussion.

Kiichi Inoue, policy panel chief of the New Conservative Party, one of the LDP's two coalition partners, agreed with Kamei that the issue of income tax bases must be discussed in the context of the entire tax system.

However, Chikara Sakaguchi, policy chief of New Komeito, the other coalition partner, said the income tax threshold could be lowered after a thorough review of the income tax system is conducted.

In the opposition camp, led by the DPJ, the Liberal Party approved the proposal, which has already been incorporated into the DPJ's platform ahead of the June 25 House of Representatives general election. The Japanese Communist Party and the Social Democratic Party, however, opposed it.

Liberal Party Secretary General Hirohisa Fujii said the government should lower the limit and offset the increased burden by granting allowances to households with children.

JCP policy chief Hideyo Fudesaka warned that the proposal will lead to a heavier burden for ordinary taxpayers.

SDP policy head Kenichi Hamada said the issue should be studied comprehensively along with income, assets and consumption.

A four-member household including two children with one aged 15 or under is now exempt from income taxation if its annual income is 3,821,000 yen or less.