Prime Minister Naoto Kan said Monday it would take at least two to three years to increase the consumption tax.

Kan's comments came as public support for his Cabinet slipped by 6 percentage points from a week earlier to 58.8 percent, according to a weekend Kyodo survey. He brought up raising the tax Thursday.

During a news conference Monday at the Prime Minister's Official Residence summing up the Diet session that ended last week, Kan reiterated his strong determination to restructure the tax system, going as far as mentioning the possibility of holding a snap Lower House election once his administration settles on a blueprint.