Their disquiet showed in the country's regional elections, held earlier in March, in which a great number of voters abandoned Chancellor Angela Merkel's conservatives for the anti-immigrant party Alternative for Germany (AfD).
The legislation proposed by De Maiziere — a conservatives himself — followed soon thereafter. He expects migrants to do their best to assimilate, in exchange for the opportunity to live in Germany and for the assistance they get like language lessons, social benefits and housing.
"For those who refuse to learn German, for those who refuse to allow their relatives to integrate — for instance women or girls — for those who reject job offers: for them, there cannot be an unlimited settlement permit after three years," he told ARD TV.
De Maiziere added that the permitted period of stay for refugees has to depend on the success of their integration efforts.
"We must not only support integration but demand it," he told Bild.
Gabriel's Social Democrats, the junior partner in Germany's ruling coalition with Merkel's conservatives, also saw significant losses in the recent elections.
Around a million migrants arrived in Germany in 2015. According to de Maiziere, some 100,000 more have arrived so far this year.