Boris, like Ken before him, is getting some serious flak because of allegations about one of his advisers.
The mayor is allowed to appoint a number of individuals to posts such as these. They are in a nether world between paid public servant and political appointee.
They attract a partisan press attention so that they cannot fulfil the role of paid public servants, and yet they do not have any accountability other than to the mayor who appointed them, which raises serious concerns about their political responsibilities.
The Greater London Authority Acts should be amended. The mayor should be able to appoint a cabinet, but he should do so from the members of the London Assembly.
If the Mayor wants particular people to particular jobs, he should be able to appoint them, but political and democratic responsibility should reside with the elected mayor and a cabinet drawn from the members of the Greater London Assembly. Operational responsibility should reside with officials.
The same system as set out in in the 2000 Local Government Act. Use this, not the failed mayoral cabinet experiment.