Posterior marginal distributions of cosmological parameters obtained by Plik on a single FFP6 realisation, under different assumptions on the foreground model. Red thick lines correspond to the foreground model parametrisation described in Sect. 3 with fixed γ^CIB. Purple lines (resp. green, grey) show the effect of leaving γ^CIB free (resp. letting γ^Dust free, or fixing γ^CIB to 0.4, 2σ away from the peak posterior value). Finally, the blue lines correspond to the analysis made on CMB-only simulations. The input values of the parameters of the simulation are shown as dashed vertical lines.