  Optical polarisation measurements are key tests for different models of the
pulsar magnetosphere. Furthermore, comparing the relative orientation of the
phase-averaged linear polarisation direction and the pulsar proper motion
vector may unveil a peculiar alignment, clearly seen in the Crab pulsar. Our
goal is to obtain the first measurement of the phase-averaged optical linear
polarisation of the fifth brightest optical pulsar, PSR\, B0656+14, which has
also a precisely measured proper motion, and verify a possible alignment
between the polarisation direction and the proper motion vector. We carried out
observations with the Very Large Telescope (VLT) to measure the phase-averaged
optical polarisation degree (P.D.) and position angle (P.A.) of PSR B0656+14.
We measured a P.D. of $11.9\%\pm5.5\%$ and a P.A. of $125.8\degr\pm13.2\degr$,
measured East of North. Albeit of marginal significance, this is the first
measurement of the phase-averaged optical P. D. for this pulsar. Moreover, we
found that the P.A. of the phase-averaged polarisation vector is close to that
of the pulsar proper motion ($93.12\degr\pm0.38\degr$).Deeper observations are
needed to confirm our polarisation measurement of \psr, whereas polarisation
measurements for more pulsars will better assess possible correlations of the
polarisation degree with the pulsar parameters.
