  (shortened) We investigate the properties of Galactic WR stars and their
environment to identify evolutionary channels that may lead to the formation of
LGRBs. To this purpose we compile available information on the
spectropolarimetric properties, the presence of CS ejecta, and the CS
velocities in the environment of Galactic WR stars. We use linear
line-depolarization as an indicator of rotation, nebular morphology as an
indicator of stellar ejecta, and velocity patterns in UV absorption features as
an indicator of increased velocities in the CS environment. We find that the
~23% WR stars with "possible ejecta nebulae" dominate the population of WR
stars with spectropolarimetric signatures of rotation, while WR stars without
such nebulae only rarely show indications of rotation. The corresponding
objects are most likely in an early stage after a preceding RSG or LBV phase,
and have not yet lost their angular momenta due to the strong mass-loss in the
WR phase. From their photometric periods we estimate rotation parameters in the
range omega = 0.04...0.25, corresponding to moderate rotation speeds of
36...120 km/s. These values are very uncertain, but comply with the specific
surface angular momentum requirement for LGRB progenitors. Our results indicate
that, in the Galaxy, mainly "young" WR stars shortly after a RSG/LBV phase show
spectropolarimetric signatures of rotation. Their rotation rates are thus
likely enhanced with respect to the majority of Galactic WR stars. According to
their estimated specific surface angular momenta, a subgroup of stars exploding
in this phase may represent an evolutionary channel towards LGRBs at high
metallicities, comparable to the Galaxy.
