Veteran Liberal Democratic Party lawmaker Taro Kono is calling for a drastic policy shift that Prime Minister Shinzo Abe is loath to accept: open up Japan to blue-collar foreign workers.

For Japan, which has for years grappled with a fertility rate of less than 1.5, the only way to survive as a viable economy is to accept immigrants, Kono said at a Tokyo symposium on immigration policy last week.

"Even if some miracle happens and Japan's fertility rate shoots up to 2.0 tomorrow, it takes these babies about 20 years to contribute to our country's workforce. It's obvious to everybody's eyes that the only option we have is to accept workers from overseas," he said.