Dozens of protesters outside the Diet called Wednesday for abolishment of the controversial health-care insurance system covering the "later-stage elderly" aged 75 and older.

The group was made up of members of labor unions, medical staff and other organizations. Lawmakers from four opposition parties joined the gathering and helped shout for the system to be killed.

A bill introduced by opposition parties to abolish the controversial system cleared the Upper House in June and is now awaiting deliberation in the Lower House.

"From the beginning, we have argued that it is nonsense for a health-care system to have a separate category for people 75 and older, and it would definitely not be accepted by the people," Masayuki Naoshima, policy research chairman of the Democratic Party of Japan, told the people staging the sit-in outside the Diet.

The system, introduced in April, has upset many seniors because it separates people aged 75 and older from the insurance system covering younger generations. Many elderly have charged that the system discriminates against them.

The system automatically deducts health insurance premiums from seniors' public pension benefits, another reason for its unpopularity among the elderly who depend on those benefits.

The government's aim in adopting the new system was to have the elderly more fairly share the nation's swelling medical bill.

Although the ruling coalition supported putting the system in place, Prime Minister Taro Aso and Health, Labor and Welfare Minister Yoichi Masuzoe have started saying it needs a fundamental review, but they have not called for its outright abolition.