The Tokyo suburb of Musashino has filed an appeal against a Tokyo District Court ruling that ordered it to grant a National Health Insurance card to a Chinese woman who had overstayed her visa, officials said Wednesday.

The court ruled July 16 that the woman, whose name was withheld, could substantiate her claim to stable and continued residency in Japan, legally the sole criterion for National Health Insurance. "This ruling may very well serve to lengthen the stay of foreigners who are here illegally," said Masanori Saiga, director of Musashino's civic affairs department, who said the city filed the appeal Monday.

He said the court failed to provide a plausible alternative for the guidelines previously laid out by the Health and Welfare Ministry. The ministry had specified that a valid visa of one year was necessary to obtain National Health Insurance.

The court ruled that the circumstances of immigration, possession of a valid visa upon entrance and the length of a foreigner's stay should also be considered. "It is impossible for a city to apply national immigration laws and make decisions based on these criteria," Saiga said. Once the central government renews the woman's visa, the city can issue a National Health Insurance card, he said.