Some 40,000 foreign workers are expected to be accepted in the first year the new visa categories go into effect, with the total rising to 250,000 after five years, government sources said Saturday.

The government, which submitted a related bill to revise the immigration control law Friday, does not plan to set a ceiling on the acceptance of foreign nationals under the envisaged system, according to the sources.

The bill was submitted with the aim of getting it through the Diet during the ongoing session that ends on Dec. 10. Lawmakers hope to introduce the new system next April.

Visas under the system will be granted to foreign nationals with “specified skills,” including blue-collar workers.

The government is considering limiting the issuance of visas under the new categories to 14 domestic industries facing severe labor shortages, such as the construction, farming and restaurant sectors.

As of October 2017, about 1.28 million foreign nationals worked in Japan.

Anticipating an increase of hundreds of thousands of foreign workers following the establishment of the new system, the government is poised to advance preparations, including in the fields of medical services and education.

The Cabinet of Prime Minister Shinzo Abe is hoping to introduce more blue collar workers as Japan is facing an acute labor shortage due to its aging and shrinking population.

But the government has insisted the new visa system is not intended to bring in immigrants. The government defines an immigration policy as one that allows in foreign nationals with their family members indefinitely. They are also included when counting the national population.

The new plan to allow in foreign workers, however, has drawn criticism from opposition parties, who argue the government hasn’t yet figured out how to integrate foreign nationals into still-conservative Japanese society.

During a recent Diet session, Akira Nagatsuma, an Lower House member of the Constitutional Democratic Party of Japan, had demanded that the government disclose its estimate of how many workers would be introduced under the visa system. Justice Minister Takashi Yamashita only said the government was still working to estimate it.