Context : Wolf-Rayet ( WR ) stars with fast rotating cores are thought to be the direct progenitors of long-duration gamma-ray bursts ( LGRBs ) .
A well accepted evolutionary channel towards LGRBs is chemically-homogeneous evolution at low metallicities , which completely avoids a red supergiant ( RSG ) , or luminous blue variable ( LBV ) phase .
On the other hand , strong absorption features with velocities of several hundred km/s have been found in some LGRB afterglow spectra ( GRB 020813 and GRB 021004 ) , which have been attributed to dense circumstellar ( CS ) material that has been ejected in a previous RSG or LBV phase , and is interacting with a fast WR-type stellar wind .

Aims : Here we investigate the properties of Galactic WR stars and their environment to identify similar evolutionary channels that may lead to the formation of LGRBs .

Methods : We compile available information on the spectropolarimetric properties of 29 WR stars , the presence of CS ejecta for 172 WR stars , and the CS velocities in the environment of 34 WR stars in the Galaxy .
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 .

Results : Based on previous nebular classifications , we determine an incidence rate of \sim 23 % of WR stars with “ possible ejecta nebulae ” in the Galaxy .
We find that this group of objects dominates the population of WR stars with spectropolarimetric signatures of rotation , while WR stars without such nebulae only rarely show indications of rotation .
This confirms the correlation between rotation and CS ejecta from our previous work .
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 = \varv _ { rot } / \varv _ { crit } = 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 .
From UV absorption profiles we only find weak evidence for a correlation between rotation and increased CS velocities .
In particular , the CS velocities of Galactic WR stars are much lower than what is observed for GRB 020813 and GRB 021004 .

Conclusions : Our results indicate that , in the Galaxy , “ young ” WR stars shortly after a RSG/LBV phase , show spectropolarimetric signatures of rotation .
Their rotation rates are likely to be 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 .
Although the UV absorption features in our sample turn out to be different from those observed in GRB 020813 and GRB 021004 , it is interesting that for three WR stars with signatures of rotation , UV absorptions have previously been attributed to extended CS structures .
The large size of these structures ( r \sim 100 pc ) can account for the observed stability of the absorbing material in LGRB afterglows against ionizing radiation from the GRB itself .
This may resolve a fundamental problem with the interpretation of the afterglow features as CS material .