  Context: The Large Magellanic Cloud (LMC) internal kinematics have been
studied in unprecedented depth thanks to the excellent quality of the Gaia
mission data, revealing the disc's non-axisymmetric structure. Aims: We want to
constrain the LMC bar pattern speed using the astrometric and spectroscopic
data from the Gaia mission. Methods: We apply three methods to evaluate the bar
pattern speed: it is measured through the Tremaine-Weinberg (TW) method, the
Dehnen method and a bisymmetric velocity (BV) model. The methods provide
additional information on the bar properties such as the corotation radius and
the bar length and strength. The validity of the methods is tested with
numerical simulations. Results: A wide range of pattern speeds are inferred by
the TW method, owing to a strong dependency on the orientation of the galaxy
frame and the viewing angle of the bar perturbation. The simulated bar pattern
speeds (corotation radii, respectively) are well recovered by the Dehnen method
(BV model). Applied to the LMC data, the Dehnen method finds a pattern speed
Omega_p = -1.0 +/- 0.5 km s-1 kpc-1, thus corresponding to a bar which barely
rotates, slightly counter-rotating with respect to the LMC disc. The BV method
finds a LMC bar corotation radius of Rc = 4.20 +/- 0.25 kpc, corresponding to a
pattern speed Omega_p = 18.5^{+1.2}_{-1.1} km s-1 kpc-1. Conclusions: It is not
possible to decide which global value best represents an LMC bar pattern speed
with the TW method, due to the strong variation with the orientation of the
reference frame. The non-rotating bar from the Dehnen method would be at odds
with the structure and kinematics of the LMC disc. The BV method result is
consistent with previous estimates and gives a bar corotation-to-length ratio
of 1.8 +/- 0.1, which makes the LMC hosting a slow bar.
