In the latest sign that the ruling Liberal Democratic Party will not reform a tax break that has long been viewed as a disincentive for working women, Secretary-General Toshihiro Nikai appeared to walk back his earlier support for the reform.

The spousal tax break reduces the annual taxable income of a household's top earner by ¥380,000, but is forfeited if the spouse earns more than ¥1.03 million a year.

"We will make a cautious decision" about whether to ax the tax break, Nakai told reporters at a regular news briefing Friday.