(Reuters) - European Union countries must uphold the rule of law and not enter a race to the bottom when faced with migrants and refugees trying to enter the bloc, the UN High Commissioner for Refugees told European lawmakers on Wednesday.

       "These challenges simply do not justify the knee-jerk reaction we have seen in some places - the irresponsible xenophobic discourse, the walls and barbed wire, the violent push-backs that include the beating of refugees and migrants," Filippo Grandi told the European Parliament.

       "The European Union, a union based on the rule of law, should and can do better and in matters of rule of law continue to be an example to others."

       (Reporting by Sabine Siebold)