One of the commonest things I read these days are arguments that Cameron (and the Tories) are leaving behind something called "core conservative values". Accordingly, the values which make up small 'c' conservatism are - broadly speaking - small government and low tax. It thus follows that because Cameron has not announced policies to reduce the size of government or to specifically lower tax he is no longer conservative. In my view that argument is fundamentally flawed because it starts from false premises. Instead of viewing Cameron's leadership from a starting point of conservative values (or rather ends), we should start by seeing the leadership in terms of conservative principles (or rather means).
The question is what are those principles? Arguably conservatism comes down to two things, change and complexity. These two principles should not to be considered in isolation though as they are interdependent upon each other. The first principle of change refers directly to the conservative approach to establishment. The conservative will incline toward maintaining the established order, or at least where it does change things those changes will avoid overt radicalism - continuity (even if it is only perceived) is the key. The second principle of complexity relates to the conservative view of the world. Put simply, conservatism rejects grand abstracted narratives of society and human affairs. Human affairs are far more complex than that, and policy, as a result, should reflect that complexity. Policy put forward by the conservative will always be based on measurable observations of how things are working rather than abstractions of how things ought to be working. The conservative will therefore equally reject socialism as he will reject hayekism, for both fail to acknowledge the complex and unpredictable nature of society and human affairs.
Given the two principles of conservatism outlined (very briefly) above, are Cameron and the Tories acting within them? I think the answer is "yes" but I think it needs qualification. There is, some would argue, evidence that Cameron is not following the principle of change in relation to the party itself, thus to say he follows conservative principles is contradictory. It's certainly true that Cameron has made much noise of the need for the party to "change". However, this "change" refers to the perception of what the party is about. Since the 1970s the party has not been directed in line with conservative principles. It may have had conservative values as its ends, but it's means to them were naked radicalism. When Cameron talks about the need for the Conservative Party to change, I think he is referring far more for the need for it to be conservative again and leave its radicalism behind. That does not mean we reject what Thatcher did as wrong, we just have to acknowledge that she was anything but conservative.
It seems to me that the criticism that Cameron is leaving core conservative values behind fails when held in comparison to conservative principles. However, I also think that those who make the criticism are radicals rather than conservatives.