TOKYO, June 29 (Xinhua) -- Japan's Diet enacted a labor reform bill on Friday purportedly aimed at addressing the country's pervasive overtime culture by implementing work-style regulations amid calls from the opposition camp the reforms could be counter-intuitive.

The ruling bloc, led by Japanese Prime Minister Shinzo Abe's Liberal Democratic Party (LDP), failed to get the bill passed through the lower house at its first attempt, amid strong resistance from the opposition camp, who argued that the new bill could in fact encourage longer working hours.

But the bill, which sees eight labor-related laws revised, cleared the upper house plenary session Friday by a majority vote of the ruling bloc, with some opposition lawmakers also supporting the bill.

"The legislation has been enacted to allow people to have different work styles, including while raising children or caring for the elderly," Abe was quoted as telling a press briefing at his office following the bill's enactment.

The main opposition Constitutional Democratic Party of Japan (CDPJ) and other parties have maintained, however, that the bill could lead to more instances of "karoshi," or death by overwork.

But a modified version of the bill cleared the lower house last month backed by the ruling bloc.

The bill now legally limits overtime hours, stipulates equal treatment for regular and non-regular workers, but, controversially, exempts highly-skilled professional workers, with high incomes, from working-hour regulations.

The exemption for this category of workers, with business lobbies encouraging firms to give such professionals 104 days off from work a year, is supposed to enable a more flexible style of work.

But opponents to the "white collar overtime exemption" system, applicable to those whose annual earnings are in excess of 10.75 million yen (97,000 U.S. dollars), believe that the scheme is tantamount to a zero overtime system.

The bill's revisions included a legal limit of 100 hours overtime per month and 720 hours per year.

Many opposition lawmakers who tried to block the legislation maintained that more deaths from overtime work could result from the exemption system and argued that the scheme is counter-intuitive to the government's purpose of reforming Japan's working style.

When voting took place in the lower house last month, a number of families who had lost loved ones who had died or committed suicide due to overwork, held photographs of the deceased and called for the bill to be scrapped.

On Friday, representatives of the organization advocating for the families of individuals who died of overwork expressed their disappointment and anger at the outcome.

The group's leader Emiko Teranishi, whose husband committed suicide due to depression caused by the strain of too much overtime, said she felt the families of those who had lost loved ones to "karoshi" felt powerless.

The group again implored the government to scrap the bill.

Opposition parties on Friday also continued to slam the bill for being forcibly enacted by the ruling bloc's overwhelming majority in parliament.

Akira Koike, head of the secretariat of the opposition Japanese Communist Party, was quoted as saying "the worst postwar labor legislation change had been forced through parliament by power of numbers."