A panel of the ruling Liberal Democratic Party will study a wide range of issues related to revising the Imperial House Law, including ways to preserve the male line of Imperial succession, LDP policy chief Hidenao Nakagawa said.

Nakagawa said on a TV Asahi Sunday talk show that he wants to have the panel "fully study and discuss ways to preserve the male line."

The panel should discuss both allowing female monarchs and preserving the male-line tradition, he said.

The LDP panel has put off starting its discussion on revising the Imperial House Law until the end of this month, following the Imperial Household Agency's announcement Feb. 7 that Princess Kiko, the wife of Emperor Akihito's younger son, Prince Akishino, is pregnant.

The news has prompted Prime Minister Junichiro Koizumi to scrap his plan to quickly submit a bill to the Diet that would allow females and their descendants to ascend to the throne.

The government had been preparing to submit the bill to revise the Imperial House Law in accordance with a report compiled in November by Koizumi's advisory panel, which proposed allowing females and their descendants to reign with the priority of succession given to the emperor's first-born child regardless of gender.

Conservative Diet members and academics have reacted against the proposal, arguing that allowing a descendant of a female monarch to reign would result in breaking the Imperial line that has been preserved historically by passing down the throne to male-line heirs, regardless of gender.

The 1947 Imperial House Law specifies that only males who have emperors on their fathers' side can ascend to the throne. However, no royal male has been born since 1965, stirring concerns over a possible succession crisis.