Japan’s Princess Kiko on Wednesday morning gave birth to a baby boy, the first male heir to the imperial throne in 41 years.

The baby was born by a caesarean operation at 8:27 am local time (23:27 GMT), weighing 2,558g. The 39-year-old Princess and baby are both fine, government representatives reported.

The baby, who is the fourth grandchild of the Emperor and Empress, stands third in line to the Chrysanthemum throne, after Crown Prince Naruhito, 46, and Prince Akishino, the baby’s father.

The birth is likely to put a damper on efforts to revise the Imperial House Law to allow female monarchs and their descendants to inherit the throne.

News of Princess Kiko’s pregnancy stunned Japan when it was announced in February, just as debate in the Diet on whether or not to revise the law was reaching a climax.

Last November, an expert panel, appointed by Prime Minister Junichiro Koizumi, recommended changing the 1947 law to allow the emperor’s first child to succeed the throne, regardless of sex. The new law would have made Princess Aiko, 4, daughter to the Crown Prince and Princess, next in line to succeed her father.

The Financial Times Limited 2006