On 18 April 2012, the government of Switzerland announced the usage of the "pressure valve clause" ("Ventilklausel") from 1 May 2012. In the following twelve months, the number of work permissions issued to citizens from EU-8 countries is capped at 2'000.
 
The EU-8 countries are the Czech Republic, Estonia, Hungary, Latvia, Lithuana, Poland, Slovakia, and Slovenia.
 
The "pressure valve clause" had been included in the Swiss-EU agreement on the free movement of labor after the latest EU-accessions. Until the full implementation of the agreement on 31 May 2014, Switzerland may cap the issuance of work permissions if annual inflows from these countries exceed the prior three-year average by 10 percent.
 
In the year prior to the restriction, a total of about 6'000 such permissions had been issued. According to the Swiss government the relevant three-year average lay at 2'075 permissions.
 
Update: On 24 April 2013, Switzerland prolonged the "pressure value clause" for EU-8 countries until 31 May 2014.
 
On 15 May 2013, Switzerland announced that from 1 June 2013, the clause will also apply to EU-17 countries (related measure).