If I remember correctly Sidney Weintraub used for the first time the term "bastard Keynesianism" in a letter he wrote to Joan Robinson (I think in 1961)  with reference to American Keynesians who followed Samuelson's 45 degree diagram.
I will let you know more in detail the date of the letter.
Antonella Rancan

Il giorno 05/apr/2011, alle ore 16.27, Alan Freeman ha scritto:

> Dear friends
> I am about to publish an article in which I wish to refer to Joan Robinson's
> use of the term 'Bastard Keynesianism'. Does anyone know of a citable
> source, preferably by Robinson, that could accompany the reference? The more
> explanation this source provides, the better, though of course, it is also
> important to trace the term back to its original first usage if this can be
> done.
> 
> Regards
> Alan Freeman
>