The proposal, presented in the Riksdag on Friday, also calls for buses and trucks to come with the devices as well. According to the party, one in four traffic fatalities could be prevented with mandatory ignition locks.
The party's traffic committee chairman Anders Ygeman is in favour of the government's proposal on ignition locks as an alternative to revoking driving privileges for drunk driving offenses.
However, the Social Democrats want to go one step further with even more stringent legislation, including seeking an exemption from the EU that would allow Sweden to introduce ignition locks in all new cars.
"Every fourth traffic fatality could be prevented if we introduced mandatory ignition locks. Additionally, it would save society about 6 billion kronor ($877 million)," said Ygeman.
Ygeman quoted figures from data compiled from a Social Democratic report in 2004.
When asked how much it would cost the automobile industry, Ygeman said, "I think there will be rather minimal costs attached. When one begins mass production, it will become relatively inexpensive."
Stockholm public transport operator SL announced in September that it will install ignition locks on all of its buses within the next two years, ensuring drivers who have been drinking cannot start their vehicles.