From the New Shopper

It's got to be more than £1m per term in office. What is it the mayor does that the councillors can't do?

Interesting, the Mayor has just appointed two new cabinet members - each claiming an extra £15,298 a year.
The article says...
Mayor of Lewisham Sir Steve Bullock’s nominations for his new cabinet, which will increase in size from seven to nine people, the maximum allowed, will be confirmed at the AGM on May 26.

Among them are Councillors Joan Millbank and Damien Egan who take on the new roles of member for the Third Sector and member for Strategy and Communications respectively.

Cabinet members get an allowance of £15,298 on top of their £9,812 basic rate