Former Foreign Minister Yohei Kono, who is suffering from hepatitis C, may undergo a transplant operation Tuesday in which he will receive part of his son's liver, hospital sources said Monday.

Tests carried out Monday on Taro Kono's liver and cardiopulmonary functions show that the 39-year-old Lower House member can safely donate part of his liver to his 65-year-old father, the sources said.

Yohei Kono twice served as foreign minister and now heads a small faction in the Liberal Democratic Party, while Taro Kono is a parliamentary secretary at the Public Management, Home Affairs, Posts and Telecommunications Ministry. They are both currently hospitalized, the sources said.

The Tokyo hospital in question is preparing for the operation and is monitoring the condition of Yohei Kono, they said.

Partial liver transplant operations were previously thought to be ineffective in the treatment of hepatitis C. This was because patients whose liver functions initially improved after an operation later experienced liver damage from the remnants of the virus.

The number of patients undergoing such transplants has increased recently, however, due to the development of an antiviral drug that is able to suppress the symptoms of the virus.