A top German politician is calling for his country's government to tighten further the rules governing foreign takeovers just months after a law protecting carmaker Volkswagen was deemed illegal, prompting bankers to warn of a backlash against international mergers and acquisitions.

German labour minister Olaf Scholz is calling for the government to block foreign takeovers if they threaten jobs, according to business daily Handelsblatt, two months after Germany moved to tighten the law on international buyers.