The government is considering allowing more foreign workers in the manufacturing industry under a new system aimed at opening Japan’s labor market to blue-collar workers from abroad, government sources said Friday.

The idea has emerged as the government is devising a new residential status to accept more foreign workers amid the shrinking working-age population. The government is aiming to start operating the new system in April 2019.

The system was initially designed to cover five industries — agriculture, construction, lodging, nursing and shipbuilding — but the sources said small businesses engaging in metal processing may be added to the list as they are also facing a serious labor shortage.

The government is also looking to expand the scope to include other manufacturers as well as the fisheries and food-processing industries, according to the sources.

The Economy, Trade and Industry Ministry plans to listen to the views of industry groups to work out further details, they said.

Japan, known for its strict immigration policy, has so far accepted only highly skilled workers, such as researchers, interpreters and those working in the financial industry.

But many foreign nationals are working part-time at restaurants and convenience stores with the residential status of “student.” Some foreign laborers in the construction and manufacturing industries have received the status of “technical intern” under a training program for those from developing countries.

The government plans to give the new residential status to those who pass examinations on their proficiency in the relevant field and Japanese language.

With concerns lingering that the new system may lead to an influx of immigrants, the government said in June when it decided to create the new system that it plans to set a five-year limit for the stay and will basically bar foreign workers from bringing family members with them.

Foreign nationals who have stayed in Japan under the country’s technical training program will be exempted from the examinations and can extend their stay to 10 years from the current maximum five years.

The number of foreign nationals working in Japan reached a record 1.28 million as of last October, according to the Health, Labor and Welfare Ministry.