  We consider possible definitions of physical variables in QED. We demonstrate
that the condition $\partial_i A_i$$=0$ is the most convenient one because it
leads to path integral over physical components with local action. However,
other choices, as $A_3=0$, are also possible. The standard expression for
configuration space path integral in $A_3=0$ gauge is obtained starting with
reduced phase space formulation. Contrary to the claims of the paper [M.Lavelle
and D.McMullan,Phys. Lett. B316 (1993)172] the $A_3=0$ gauge is not
overconstrained.
