The description of baryons as fully relativistic bound states of quark and
glue reduces to an effective Bethe-Salpeter equation with quark-exchange in
teraction when irreducible 5-quark interactions are neglected and separable
2-quark (diquark) correlations are assumed. This covariant quark-diquark m
odel of baryons is studied with the inclusion of the quark substructure of
the diquark correlations. In order to maintain electromagnetic current cons
ervation it is then necessary to go beyond the impulse approximation. A con
served current is obtained by including the coupling of the photon to the e
xchanged quark and direct "seagull" couplings to the diquark structure. Ado
pting a simple dynamical model of constituent quarks and exploring various
parametrisations of scalar diquark correlations, the nucleon Bethe-Salpeter
equation is solved and the proton and neutron electromagnetic form factors
are calculated numerically. The resulting magnetic moments are still about
50% too small, the improvements necessary to remedy this are discussed. Th
e results obtained in this framework provide an excellent description of th
e electric form factors land charge radii) of the proton, up to a photon mo
mentum transfer of 3.5 GeV2, and the neutron.