This year could mark a turning point in Japan's family law. Calls for introducing a dual-surname option for spouses have been growing among politicians, even members of the ruling Liberal Democratic Party.

The focus is on how Prime Minister Shigeru Ishiba will handle the matter.

At a news conference last month, Ishiba expressed an intention to have his LDP deepen discussions on the matter. During the LDP presidential election in September, which he won, he expressed support for allowing dual surnames for married couples.

Currently, married couples are required by law to adopt a single surname. In 1996, the Legislative Council, an advisory panel to the justice minister, proposed allowing spouses to retain separate surnames.

Opposition parties have since submitted bills to revise the Civil Code to introduce a selective dual surname system, but they have been scrapped.

But the political landscape changed in autumn last year.

The ruling coalition lost its majority in the Lower House of parliament in a general election in October. As a result, the Constitutional Democratic Party of Japan, which grew its presence in the chamber among the opposition, took over the post of chair of the Lower House Committee on Judicial Affairs, which handles Civil Code revisions.

A CDP executive said in reference to the option, "The ordinary parliamentary session is an opportunity to realize it."

The CDP plans to submit a bill to introduce the selective dual-surname system during the next session of parliament, which is expected to be convened later this month, together with other opposition parties.

CDP leader Yoshihiko Noda said last month that his party "will make solid results and use them in elections for the Tokyo metropolitan assembly and the House of Councillors" this summer.

Seiji Maehara, co-leader of opposition Nippon Ishin no Kai, has expressed support for a selective dual-surname system and pledged that his party will discuss the matter. The Democratic Party for the People, an opposition party that made big gains in the general election, is a proponent of the system.

Outside the political world, the Japan Business Federation, or Keidanren, in June last year urged the government to introduce the system promptly. Public opinion polls show support for such a system is growing.

Tetsuo Saito, leader of the LDP's coalition partner, Komeito, said on a radio program last month, "It's time to make a decision."

He later told Ishiba that the two parties should discuss reform of the family registration system and how to choose a child's family name.

An Ishiba Cabinet member from the LDP who supports a selective dual-surname system said that LDP lawmakers should be allowed to vote on any bill on the matter at their own discretion.

Ishiba has expressed a desire to make a decision on the matter, according to an LDP member.

But there is still strong resistance to the system within the LDP, especially among conservatives who are concerned about a potential loss of family unity.

A young LDP lawmaker warned that if Ishiba forces through a selective dual-surname system, he will be driven out of office.

If Ishiba goes ahead with the change, he may come under strong criticism from conservative LDP members. As a result, an LDP executive called for a compromise.