We study the Landau-gauge quark-gluon vertex with 2 flavours of O(a) improved Wilson fermions, for several lattice spacings and quark masses. In the limit of vanishing gluon momentum, we find that all nonzero form factors have a significant infrared strength, and that the leading form factor $\lambda_1$, multiplying the tree-level vertex structure, is significantly
enhanced in the infrared compared to the quenched case. We find that all form factors are further enhanced in the infrared as the chiral and continuum limits are approached.