Now IPSA is ruling on who MPs can and can't employ

Today I hear of a new IPSA-related story which beggars belief.

An MP is seeking to employ as a research assistant someone who is a councillor and Cabinet Member on that local council. Part of that local authority falls within the boundaries of the parliamentary constituency which his prospective employer represents in the Commons.

IPSA has told the MP that it would not be appropriate to employ the councillor, seemingly over the potential for conflicts of interest.

Can this really be right?

So long as the matter is declared in the register of interests of MPs' staff and the appropriate local authority register, what can possibly be the problem? 

Shouldn't MPs be able to choose who they employ in their offices?

Jonathan Isaby