 Unions and student groups were reported to be planning further action, claiming up to 600,000 university and high school students took part in Thursday's action.They have tied any talks to withdrawal of the employment law, which is opposed by 68% of French people, according to an opinion poll published in "Le Parisien" newspaper, a rise of 13 percentage points in a week.Critics say the legal reform will create a generation of "disposable workers", but ministers tried to conciliate growing opposition, one saying no worker could be laid off without justification.