With the revised Nationality Law expected to clear the Diet soon, some ruling party lawmakers are at the last minute claiming the amendment may spark problems, such as possibly creating a "black market" in false paternal recognition.

However, it seems too late in the day for them to block passage, because the revised bill cleared the Lower House last week and the Upper House Justice Committee is entering the last stage of deliberations and is expected to vote as early as next week.

The amendment will allow children born out of wedlock to Japanese men and foreign women to obtain Japanese nationality if the father acknowledges paternity after the birth.