Political negotiations between the nation's ruling coalition are approaching a showdown over the unpopular consumption tax, which is set to rise to 10 percent from 8 percent in April 2017. A sweetener being considered has drawn scathing criticism from many economists.

The ruling Liberal Democratic Party and Komeito are in heated negotiations over a proposed low rate on fresh food and certain processed edibles to cushion the blow for low-income households. They are working toward a self-imposed deadline for agreement on Thursday.

Economists sampled oppose the proposed tax relief, dismissing it as a populist policy aimed at drawing votes ahead of the Upper House election next summer.