The Swiss Trade Union Federation says it supports an initiative calling for the introduction of a minimum wage.
Switzerland does not have a minimum wage rate, but limits are included in some collective agreements and standardised work contracts.
The initiative, the federation said at a news conference on Monday, should achieve the introduction of a minimum wage to protect workers not included in collective agreements, and ensure that collective contracts include minimum wage clauses.
There are around 200,000 workers who earn less than SFr3,500 ($3,471) a month even though they are covered by collective agreements.
A draft of the initiative text, expected to include a figure for a minimum wage, will be put to union members for approval by November 2010 at the latest.
The centre-left Social Democratic Party and the main Swiss union, Unia, have indicated they will join forces with the federation to launch the initiative.
If they collect at least 100,000 valid signatures within 18 months, the initiative will be put to a nationwide vote.
swissinfo.ch and agencies