If elected next term, the government plans to put almost 2 billion kronor into helping immigrant students and those with Swedish as a second language.
"If you're going to learn all the other subjects in school then you're going to have to master Swedish first," Education Minister Jan Björklund told Sveriges Television (SVT) on Friday.
"An imperative part of integration is being able to speak the language."
The money will be spent on training and hiring more Swedish language teachers and offering more Swedish lessons during the school week.
Statistics show that immigrant students tend to suffer when they arrive in Sweden after schooling has already kicked off.
Only 52.1 percent of them get passing grades, compared to 91 percent of students with Swedish parents.
The government proposal has at least one critic in Håkan Carlsson, the spokesman of the teacher's union (Lärarförbundet)
"We're facing a huge shortage of teachers. Every effort for schools and more teachers must be followed up by an effort for the teachers' working conditions and salaries, otherwise you won't be able to find the teachers," he told the TT news agency.