  Oxygen sequence Wolf-Rayet stars (WO) are thought to be the final evolution
phase of some high mass stars, as such they may be the progenitors of type Ic
SNe as well as potential progenitors of broad-lined Ic and long gamma-ray
bursts. We present the first spectropolarimetric observations of the Galactic
WO stars WR93b and WR102 obtained with FORS1 on the VLT. We find no sign of a
line effect, which could be expected if these stars were rapid rotators. We
also place constraints on the amplitude of a potentially undetected line
effect. This allows us to derive upper limits on the possible intrinsic
continuum polarisation, and find P$_{\rm cont}$ < 0.077 percent and P$_{\rm
cont}$ < 0.057 percent for WR93b and WR102, respectively. Furthermore, we
derive upper limits on the rotation of our WO stars by considering our results
in the context of the wind compression effect. We estimate that for an edge-on
case the rotational velocity of WR93b is v$_{\rm rot}$ < 324 km/s while for
WR102 v$_{\rm rot}$ < 234 km/s. These correspond to values of v$_{\rm
rot}$/v$_{\rm crit}$ <19 percent and <10 percent, respectively, and values of
log(j)<18.0 cm$^2$/s for WR93b and <17.6 cm^2 /s for WR102. The upper limits
found on v$_{\rm rot}$/v$_{\rm crit}$ and log(j) for our WO stars are therefore
similar to the estimates calculated for Galactic WR stars that do show a line
effect. Therefore, although the presence of a line effect in single WR stars is
indicative of fast rotation, the absence of a line effect does not rule out
significant rotation, even when considering the edge-on scenario.
