IFS and George Osborne's Economic Failure

The IFS has called out George Osborne's Autumn statement, and effectively accused the Chancellor of pulling the wool over everyone's eyes.  I can't recall this ever happening before.  The IFS is non-partisan, and gets a lot of its credibility from so being.  Along with David Cameron's implausible promises of tax cuts at the last Tory Conference, it looks more and more like a Conservative Party making undeliverable promises in the face of economic failure.