Despite repeated appeals by Kiyoshi Sasamori, chairman of the Japanese Trade Union Confederation (Rengo), to improve treatment for part-time workers during this year's spring labor offensive, nearly 44 percent of affiliated unions were found to have no such plan.

Labor sources said Sasamori wanted to increase wage levels for all workers by winning wage increases for part-time workers and at the same wanted to refute criticism that unions are satisfied with a wage gap for such workers, and that both labor and management are responsible.

Unions, however, have been reluctant to respond to Sasamori's appeals.