Swiss environmental group Ecopop petitioned to put a stricter immigration law to a popular vote. Ecopop

A referendum will be held in Switzerland on a proposed immigration law that would limit the number of foreigners moving to the country.

Swiss environmental group Ecopop successfully petitioned to put the law to a popular vote, obtaining over 100,000 signatures.

The group warned that overpopulation would put a strain on Switzerland’s natural resources. The small European country’s population currently stands at around 8 million, nearly a fourth of whom are foreigners.

"The pressure on land, nature and the countryside is considerable, and quality of life is continuously deteriorating due to a lack of living space," said Ecopop member Philippe Roch, a former director of the Swiss environment department, the BBC reported.

The law proposes capping population growth through immigration at 0.2 percent and also requires that 10 percent of foreign aid to other countries should be spent on birth control measures.

Ecopop has said that it does not support any prejudice against foreigners and that the law is only meant to protect the social and environmental stresses of overpopulation.

Switzerland’s population has increased 140 percent since 1990.