The country's largest trade union, Unia, says it supports extending Switzerland's free movement of people treaty with the European Union to Bulgaria and Romania.
However, Unia delegates at a weekend meeting in Bern said that they expected the government to improve measures to prevent wage dumping.
The extension of the free movement treaty will go to a nationwide vote on February 8.
The Swiss Trade Union Federation is expected to announce its position on the vote on Monday.
The financial crisis was also discussed by Unia delegates, who called on the cabinet to take action to prevent pension plans from increasing investments in alternative financial instruments such as hedge funds.
Unia is opposed to a new regulation due to come into effect on January 1, 2009 which will allow pension plans to do so, while decreasing their share of low-risk assets.