A similar institution is that of Chief Rabbi of the United Hebrew Congregations of the British Empire, which, however, rests exclusively on voluntary acknowledgement on the part of the congregations, and does not extend over whole groups of congregations like the Portuguese, the Reform, and the Polish organizations. The office of the "Grand Rabbin du Consistoire Central" in France is also of similar nature, but differs in that the chief rabbi acts merely in his capacity as member of the consistory, and not as hierarchic chief.