The most recent one is Cameron's declaration that the Office for Budget Responsibility, something that he set up in order to forecast economic conditions and the size of the deficit, does not regard the spending cuts and tax rises as being responsible for the weak economy. The OBR then pointed out, in a direct rebuttal of Cameron's remarks, that it does believe that these are factors that contributed to the stagnation of the economy, and that it has been repeatedly saying this for the last 3 years.
In fact, to claim that austerity has not hurt the economy is not that sensible a thing to do, since it involves removing money from the people in order to finance the debts of the government. It is going to be nothing but a drag upon the economy, at least in the short term, and is only a valid policy to take because it is making the government budget sustainable. The argument for austerity is long term security, not short term growth.
It seems strange that Cameron should claim that the OBR does not believe that cuts and tax rises are effecting the recovery, first because they do not believe anything of the sort, and secondly because he said himself that he was in for the long-haul, not short term gains.
Of course, this is not the only reason that the economy is acting like a duck in a desert, since there is the the overhang of the debt that needs to be paid off from the 2008 banking crash, as well as uncertainties in the rest of the world, which the OBR acknowledges and blames for a lot of the growth issues that we have. In fact, the OBR seems like it know what it is talking about, and would be a valuable source of information for the government, should they decide to actually listen to what it is saying.
If Cameron wants to convince us that he is running an efficient and sustainable government that understands the challenges its faces, and has a plan to solve them, then he can make use of something that he not only created, but was one of his ideas that have actually turned out alright.