Spain said it could give residency and work permits to about 900,000 undocumented migrants in the country over the next three years to help address a growing need for workers, even as other European countries embrace tougher stances on immigration.

The new rules will start in May, with government officials expecting that about 300,000 migrants will be given legal status per year until 2027. Only people who have been living in Spain for at least two years will be eligible, the government said.

Legalizing undocumented migrants is not just about “respect for human rights,” said Elma Saiz, Spain’s migration minister, in an interview with national broadcaster Radio Nacional de España. “It’s also about prosperity.”

She said Spain needs about 250,000 foreign workers a year to maintain its welfare state, given its “demographic challenges,” including one of the lowest birthrates in Europe.

Countries in Europe have shrinking working-age populations, with businesses reporting a chronic shortage of workers, especially in sectors like caring for older people, agriculture and hospitality. Yet there is only a limited legal path for migration to the continent, and governments have been slow to expand it as anti-immigrant sentiment grows across Europe.

Pedro Sánchez, the prime minister of Spain, has spoken often about the country’s dire need for labor and said last month that immigration was critical for economic growth. The key to migration, he said, “is in managing it well.”