TOKYO (Reuters) - Japan stepped closer to amending its century-old sex crime law on Thursday when parliament’s lower house approved a bill to widen the definition of rape, make prison sentences lengthier and allow prosecution when victims do not press charges.

Representatives of civil groups urging reform of Japan's archaic sex crimes law hand Justice Minister Katsutoshi Kaneda (L) a petition in Tokyo, Japan, in this photo taken by Kyodo on June 7, 2017. Mandatory credit Kyodo/via REUTERS

Victims and activists have long campaigned for changes to the 1907 law, as society’s attitudes toward rape victims are still chilly and many stay silent from shame or fear of criticism.

Less than 5 percent of women who were forced to have sexual intercourse consulted police, according to government data for 2014, and only about one-third spoke to anyone, including friends.

“This is a chance to change the penal code after 100 years: a once in a century opportunity,” said an online petition by more than 30,000 people. The current law was introduced before women could vote and its main intent was to protect “family honor and pedigree”, the petition added.

Enactment of the proposed changes requires approval of parliament’s upper chamber. Time is running short in the current parliamentary session, due to end on June 18, though media reports suggest it could be extended.

The bill’s passage has been caught up in wrangling over a separate anti-conspiracy bill that Prime Minister Shinzo Abe’s ruling coalition is trying to push through.

The proposed revisions would broaden the definition of rape, now limited to vaginal penetration by a penis, to a more inclusive “forced sexual intercourse” that includes forced anal and oral sex, thereby also recognizing males as possible victims.

Victims would no longer be required to press charges themselves in order for the offender to be prosecuted, and the minimum sentence would be raised to five years imprisonment from three.

The revised law would also drop a requirement that sexual abuse by parents or guardians against minors under the age of 18 should involve “violence or intimidation” to be considered a crime.

Four civil groups campaigning for legal changes presented a petition to the justice minister on Wednesday urging that the condition be removed for all victims, since a lack of physical resistance should not be taken to indicate that the sex was consensual, especially in cases of power harassment.

“These revisions are necessary, although they are only partial and come too late,” Keiko Ota, a lawyer campaigning on the issue, told Reuters. “But the ruling parties have taken the revisions hostage in order to pass the anti-conspiracy act.”