VIENNA (Reuters) - Austria s conservative People s Party wants children who do not speak  sufficient  German to take compulsory language classes as a condition for being allowed to attend school, party leader Sebastian Kurz said on Wednesday.  Tens of thousands of migrants from the Middle East, Afghanistan and Africa have arrived in Austria in the past two years. Their integration has become an important political topic and Kurz, whose party is the junior partner in a coalition government with the Social Democrats, has gained in popularity because of his hard stance on immigration. Though his proposal ostensibly applies to all children, public debate has centered around those from migrant backgrounds, most of whom are currently placed at school according to age.  They receive separate language lessons but teachers have said that this is not enough to integrate them.  One can only follow the curriculum if one s German is good enough,  Kurz said at a news conference in Salzburg, where he presented his party s education program for parliamentary elections on Oct. 15.  Who starts at school needs to understand the teaching language,  the party chief said, echoing demands from the far-right Freedom Party.  