By Ray Furlong
BBC News, Berlin
Germany's education system has been severely criticised by a UN special rapporteur who carried out an eight-day inspection of the country's schools.
The children of immigrant families are at a disadvantage: UN report
Vernor Munoz said the system was excluding children from poor families and immigrant backgrounds from the chance of a good education.
The UN's human rights commission sent Mr Munoz to inspect Germany's schools and kindergartens.
The problems he drew attention to are no surprise for Germany.
But the mere fact that he was coming here was taken as a further sign that German schools are not up to standard, following a poor showing in a major international study four years ago.
As a major industrial country, Germany has identified an educated workforce as the key to its economic future.
Mr Munoz said the problems were caused by the structure of the education system, which usually selects children at the age of 10 to go to either a grammar school or a vocational one.
This was too early, he said, and meant the potential of many children was not being exploited.
Education Minister Annette Shavan responded by saying there were a lot of good points to Germany's education system.
But she added that the government would work to decouple the link between academic success and social background.