Sir Alan Budd, the first chairman of the Office for Budget Responsibility , said he believed the OBR had rebuked David Cameron because he "made an error'.
I think it could be regarded as something of a rebuke.
I think he is correcting a statement that the Prime Minister has made and the important thing is that the Prime Minister is attributing a view to the OBR which it doesn't hold and I think when that happens it is absolutely right to write to the Prime Minister and point out that he has made an error.
Sir Alan was talking to BBC Radio 4's PM program.
More top news
Jamie Oliver turned down the offer of playing a hobbit in the movie adaptation of the book by JRR Tolkien, the TV chef has revealed.
Children are being put at risk as 11% of posts for permanent children's social workers remain unfilled, experts have warned.
A Network Rail boss who presided over the Christmas trains chaos will not receive a bonus of more than £300,000 when he leaves in February