  According to extensive experimental findings, the Ginzburg temperature
$t_{G}$ for ionic fluids differs substantially from that of nonionic fluids
[Schr\"oer W., Weig\"{a}rtner H. 2004 {\it Pure Appl. Chem.} {\bf 76} 19]. A
theoretical investigation of this outcome is proposed here by a mean field
analysis of the interplay of short and long range interactions on the value of
$t_{G}$. We consider a quite general continuous charge-asymmetric model made of
charged hard spheres with additional short-range interactions (without
electrostatic interactions the model belongs to the same universality class as
the 3D Ising model). The effective Landau-Ginzburg Hamiltonian of the full
system near its gas-liquid critical point is derived from which the Ginzburg
temperature is calculated as a function of the ionicity. The results obtained
in this way for $t_{G}$ are in good qualitative and sufficient quantitative
agreement with available experimental data.
