While the SVP is unhappy with the implementation proposals currently going through parliament it will not launch another referendum, Party president Albert Rösti told the SRF television Tagesschau news programme on Wednesday evening.
“We made a clear decision at a party leadership meeting not to call a referendum,” Rösti told the programme.
“We would be asking people to vote on something that would achieve nothing,” he said, referring to opposition in parliament to implementing tough immigration quotas.
The right-wing party spearheaded the initiative to curb mass immigration that was approved by voters in February 2014.
Since then the government and parliament have been seeking ways to implement the measures that will not put Switzerland's relations with the European Union in jeopardy.
A large number of bilateral agreements, including one on the free movement of people, are at the heart of Swiss-EU relations.
Curbs on EU immigration would contravene that agreement.
Parliament has been considering ‘light' forms of implementation of the mass immigration initiative, ranging from some quotas for foreign workers to prioritizing the resident Swiss workforce.
Consensus is forming for a proposal that would require employers in job sectors affected by higher than average unemployment to report vacancies to unemployment offices and invite resident candidates for interview.
If Swiss applicants are subsequently turned down in favour of foreign applicants, the companies would have to justify why.
However, the details still have to be ironed out.
The SVP wants its initiative to be strictly implemented, with rigid quotas on immigration put in place.
Rösti said that if a watered-down version of the initiative was implemented people would notice immigration rising again.
If this happened, the SVP would launch an initiative to scrap the bilateral agreements with the EU.