 The 36 metropolitan borough councils are also the sole elected local government units in their areas (except for parish councils in a few locations), but share strategic functions with joint boards and arrangements.On the other hand, the City of London Corporation and the 32 London borough councils, although they have a high degree of autonomy, share strategic functions with the directly elected Mayor of London and London Assembly.Unitary authorities should not be confused with another formation in English local government, the combined authority.