A strike alert in support of their pay rise demands has been declared by nine trade unions in the Czech public sector, including those of public administration, school, health-care and culture workers, and another four unions back the step, Pavel Bendar has told CTK on the unions' behalf. The unions' leaders agreed on a step-by-step declaration of a strike alert on June 8, out of dissatisfaction with the hitherto pay rise negotiations with the cabinet.