  The investigation of $e \gamma \to \nu W$ process is crucial for a possible
high energy $e \gamma$ or $\gamma \gamma$ collider since it offers the
possibility for both new physics discovery and precision measurements. The
polarization of the initial beam is a limiting factor for the systematic errors
in both cases. This note addresses the feasibility of making a measurement of
the initial electron beam polarization with relative statistical error of one
percent. Generator and detector level MC tools are used to obtain a realistic
event selection for the signal process at the future CLIC test facility running
at $ \sqrt{s}=150$ GeV.
