Davies left the Conservative Party to join the Labour Party benches on 26 June 2007, the night before Gordon Brown became Prime Minister of the United Kingdom. Davies made his decision public in a letter to the Conservative leader David Cameron in which he wrote: "Under your leadership the Conservative Party appears to me to have ceased collectively to believe in anything, or to stand for anything. It has no bedrock. It exists on shifting sands. A sense of mission has been replaced by a PR agenda." He went on, "I am looking forward to joining another party...which has just acquired a leader I have always greatly admired, who I believe is entirely straightforward, and who has a towering record, and a clear vision for the future of our country which I fully share." He accused Cameron of "superficiality, unreliability and an apparent lack of any clear convictions." He said that these qualities ought to "exclude you from the position of national leadership to which you aspire and which it is the presumed purpose of the Conservative Party to achieve."