OSAKA — It is time Japan realized that in order to deal with its population decline, it must accept 10 million permanent immigrants rather than a small number of migrant laborers, said the country's most prominent advocate of a radical new immigration policy.

"By 2050, Japan's population will have shrunk from the current 127 million to about 90 million, and to about 40 million by the end of the century. By my calculations, we need 10 million new immigrants by midcentury to survive as a nation," Hidenori Sakanaka, former head of the Tokyo Regional Immigration Bureau, said at a recent symposium in Osaka on Japan's future as an immigrant nation.

Over the past few years, as the reality of the combination of a declining birthrate and rapidly aging population set in, politicians, the Justice Ministry, and powerful business lobbies like the Japan Business Federation (Nippon Keidanren) have offered various proposals on how certain numbers of skilled foreign workers might be admitted.