  We use 2HEX smeared gauge configurations generated with an
$\mathrm{N}_\mathrm{f}\mathrm{=2+1}$ clover improved Wilson action to
investigate $\pi\pi$ scattering in the $\rho$ channel. The range of lattice
spacings (0.054 to 0.12 fm) and space-like extents (32 and 48) allows us to
extract the scattering parameters through the volume dependence of the
$\pi\pi$-state energies according to L\"uscher's formalism. The pion masses
(134 to 300 MeV) are light enough to allow the decay of the rho and the level
repulsion observed indicates that our data are sensitive to the interaction. We
analyse our data with a multi-channel GEVP variational formula. Our results are
in good agreement with the experimental values and consistent with a weak pion
mass dependence of the $\rho\pi\pi$ coupling constant.
