The Chancellor yesterday took time out from worrying about the drag from Europe on Britain's moribund economy to use his appearance at the Leveson Inquiry to smooth the way for the Prime Minister, who will give evidence later in the week.

Superficially at least, George Osborne did a fine job. Relaxed, composed, straightforward, he explained the haste of Jeremy Hunt's appointment to oversee News Corp's bid for BSkyB as born of necessity, given the speed with which Vince Cable's unguarded remarks about "declaring war" on Rupert Murdoch were becoming a threat to the stability of the Government. He denied that, like Mr Hunt, he was naturally sympathetic to News Corp, stressing repeatedly – if somewhat implausibly – that the issue was, to him, a "political inconvenience", nothing more. And the suggestion of a grand bargain, with support from The Sun in return for a helping hand on the BSkyB deal, was, he said, "complete nonsense".

The Chancellor was hardly less effective regarding the appointment of Andy Coulson as the Conservative – and then Downing Street – communications director. Yes, he had asked if there was more to come in relation to phone-hacking at the News of the World. Yes, he had realised that the appointment might be contentious. But, he had thought it worth the risk to secure Mr Coulson's considerable talents, and had believed in the thoroughness of the police investigation.

So far, so banal. But David Cameron cannot yet breathe easily. The Prime Minister cannot just brush aside Mr Hunt's public support for the BSkyB deal. Neither will it be sufficient to say he asked Mr Coulson about phone hacking. Neither will his over-friendly text messages to Rebekah Brooks – and use of her horse – be readily explained away. All are questions about the Prime Minister's judgement. And on that, Mr Osborne could not help him.