What possible justification can there be for this?

From The Guardian’s write up of the latest TPA report on public sector pay:

“Those earning more than the prime minister include Professor Salman Rawaf, the director of public health in Wandsworth, who has a package of up to £370,550”

I can accept that some people in the public sector with certain particularly valubale skills might have to be paid more than the PM. But I find it hard to see why Wandsworth is offering its director of public health a package worth more than a third of a million pounds. One hopes that the Tory policy which will see the Chancellor having to sign off on any public servant being paid more than the PM will put an end to this kind of excess.