  Here we discuss two consecutive MERLIN observations of the X-ray binary LS I
+61 303. The first observation shows a double-sided jet extending up to about
200 AU on both sides of a central source. The jet shows a bent S-shaped
structure similar to the one displayed by the well-known precessing jet of SS
433. The precession suggested in the first MERLIN image becomes evident in the
second one, showing a one-sided bent jet significantly rotated with respect to
the jet of the day before. We conclude that the derived precession of the
relativistic (beta=0.6) jet explains puzzling previous VLBI results. Moreover,
the fact that the precession is fast could be the explanation of the never
understood short term (days) variability of the associated gamma-ray source 2CG
135+01 / 3EG J0241+6103.
