Cameron flunks PMQs

David Cameron was the clear loser of PMQs (video link) this week. He lacked the focus and self-assurance that he had shown in previous weeks. He didn't seem to know what subject to focus on - perhaps mindful of the questions increasingly being asked about Lord Ashcroft and his tax status. Meanwhile, despite - or because of - the problems he faces, Gordon Brown seemed finally to have acquired the self-confidence he had lacked in earlier bouts. He had a good line on the party funding affair, which left Cameron looking shifty and surprisingly unsure of his ground. Brown even had a good putdown for last week's creator of the Mr Bean jibe, Vince Cable.
UPDATE: Tom Watson has helpfully published the full exchange between a Tory frontbencher David Ruffley and Andrew Neil over the Ashcroft question on his blog.