If he's wrong - if there is, in fact, a faster growth path available, which would not undermine market confidence, then the government's strategy could be making the supply side problem a self-fulfilling prophesy, by condemning us to unnecessarily slow growth which could have permanent effects on Britain's potential output.
The third anniversary of U.S. military action to liberate Iraq has brought with it a relentless stream of media and political pessimism that is unwarranted by the facts and threatens to become a self-fulfilling prophesy if it goes unchallenged.