The Swiss government is opposed to the initiative championed by the right-wing Swiss People's Party (SVP) that goes to a vote on June 14, saying it will damage cooperation with the European Union, its key trade partner, and hurt the economy.
The proposal stipulates the permanent resident population must not exceed 10 million before 2050, and that Switzerland should end its freedom of movement accord with the EU.
The new survey by polling firm GfS Bern for public broadcaster SRG conducted from April 20 to May 3, showed 47% of 19,728 respondents in favour of the proposal and 47% against.
The rest expressed no opinion. The poll had a margin of error of plus or minus 2.8 percentage points.
A survey published by another polling institute in late April showed a slight majority in favour of the initiative.
Concern about rapid population growth and pressure on public infrastructure has fed support for the proposal, although business groups warn it will jeopardise prosperity.
Switzerland's population recently breached the 9 million mark, and official data show foreign nationals accounted for more than 27% of the total by 2024.
The SVP, Switzerland's biggest party, opposes closer integration with the EU, depicting it as a threat to Swiss sovereignty and a source of excess regulation.
Swiss lawmakers are debating a Swiss-EU deal struck in late 2024 that would deepen joint economic integration.
The government wants Switzerland to consolidate ties with the EU to help protect the economy amid uncertainty fuelled in part by the trade policies of President Donald Trump's administration. In 2025, Washington hit Switzerland with the highest tariffs in Europe.
(Writing by Dave GrahamEditing by Tomasz Janowski)

An electoral poster for the right-wing Swiss People's Party (SVP) popular initiative reading 'Let's protect Switzerland. No to Switzerland of 10 million!' is attached to a fence in Charmey, Switzerland, 02 May 2026. SVP's popular initiative 'No to Switzerland of 10 million! (Sustainability Initiative)' aims to cap the permanent resident population at 10 million by 2050. On 14 June 2026, the Swiss people will vote on this popular initiative. EPA/JEAN-CHRISTOPHE BOTT