We study a spin-1/2 SU(2) model on the honeycomb lattice with nearest-neighbor antiferromagnetic exchange J that favors Néel order, and competing 6-spin interactions Q which favor a valence bond solid (VBS) state in which the bond-energies order at the "columnar" wavevector K = (2π/3,-2π/3). We present quantum Monte-Carlo evidence for a direct continuous quantum phase transition between Néel and VBS states, with exponents and logarithmic violations of scaling consistent with those at analogous

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... econfined critical points on the square lattice. Although this strongly suggests a description in terms of deconfined criticality, the measured three-fold anisotropy of the phase of the VBS order parameter shows unusual near-marginal behaviour at the critical point.