  We present the first calculations of the electromagnetic form factors of
$^3$He and $^3$H within the framework of the Covariant Spectator Theory (CST).
This first exploratory study concentrates on the sensitivity of the form
factors to the strength of the scalar meson-nucleon off-shell coupling, known
from previous studies to have a strong influence on the three-body binding
energy. Results presented here were obtained using the complete impulse
approximation (CIA), which includes contributions of relativistic origin that
appear as two-body corrections in a non-relativistic framework, such as
"Z-graphs", but omits other two and three-body currents. We compare our results
to non-relativistic calculations augmented by relativistic corrections of
${\cal O}(v/c)^2$.
