Germany's Social Democrat education minister, Edelgard Bulmahn, has scored a victory in her fight to introduce performance-related pay for university professors after the cabinet approved her reform of higher education pay and conditions.
But Conservative-led states have warned they will put up "massive opposition" to the reform.
The reform aims to make up to 25 per cent of professorial pay dependent on performance in research or teaching.
It would also create junior professorships, limited to six years, that would be open to academics as soon as they completed their PhDs in their late 20s or early 30s.
This would bypass the Habilitation , the postdoctoral thesis required to qualify as a professor, which takes an average six years and is widely considered a brake on academic careers.
Ms Bulmahn said: "This will give young scientists... the chance to teach and research independently." She called the Habilitation an outdated system that keeps young academics tied to their professors "like vassals" until their mid-30s.
"We can no longer afford to allow the best brains to emigrate abroad in search of more attractive working conditions," said Ms Bulmahn, who earlier this year travelled to the US to try to attract young German scientists back to their home country.
But the states of Bavaria, led by the Christian Social Union, and Hesse and Saxony, both led by the Christian Democrats, have announced they will fight the reform in the Bundesrat.
Hans Zehetmair, Bavarian education minister and education spokesman for the Conservative states, said they were angry that the reform would in effect abolish the Habilitation .
He said basic professorial salaries proposed by the reform were too low "to attract outstanding academics".
The reform would do away with professorial pay grades that rise with age, and replace them with a simplified salary structure common both to universities and Fachhochschulen .
Junior professors would be paid €3,250 (£2,000) a month for up to six years. If they proved themselves in this period, they would later have the chance for promotion to full professor with a basic minimum monthly salary of €3,500 plus an average €1,000 to be negotiated according to performance. The top professorial grade would receive a basic minimum of €4,250 plus an average €1,550 based on performance.
The reform means it would be up to individual states to decide the criteria for awarding performance pay. No extra government funds will be allocated to pay for the changes, although Ms Bulmahn said €175 million would be spent to help introduce the first wave of 3,000 new junior professorships over the next three years.
Kristjan Domiter, spokesman for the Hochschulverband, representing Germany's professors, said: "What we might see is rich states like Bavaria or Hesse attracting people on higher salaries at the expense of universities in poorer states."