Japan's parliament was set to vote on plans to reform organ donation laws, potentially paving the way for children to receive life-saving transplants here for the first time.
Current law bans organ transplants by children under 15, a situation which, activists say, has claimed thousands of lives and forced many families to send children in need of transplants on costly overseas trips for surgery.
Under Japanese law, transplants have been rare even for adults because of rules that require an organ donor to give prior written consent to having their organs harvested and also require their relatives to agree.
Members of the House of Representatives will vote on four amendment bills.
Under the bill proposing the most sweeping change, the age limit and the need for prior written consent would be abolished.
The other two proposals seek to lower the minimum age of donors to 12 years or to allow donations by children based on family consent while still requiring written permission for those 15 or above.
The fourth bill, submitted by lawmakers who oppose the medical concept of brain death, aims to tighten the rules further.
The medical concept of brain death remains controversial in Japan, where many religious groups argue that a person is deceased only when their heart has stopped beating and their lungs no longer function.
The first proposal to gain the support or more than half of the 480 lower house members will be sent to the upper house. Major political parties have told legislators to vote according to their conscience.
Japan adopted an Organ Transplant Law in 1997, but since then only 81 transplants have been carried out, compared to several thousand each year in the United States and several hundred annually in Europe.
The long-debated reform plans have been fast-tracked this year after the World Health Organization signalled it would ask signatory nations in early 2010 to limit organ transplants to within their national boundaries.
In the move against so-called transplant tourism, which seeks to limit abuses, Australia, Britain and Germany have already announced they will refuse Japanese patients seeking organ transplants.