He speech to the Conservative Party conference in Manchester on Wednesday will be watched more closely than ever.
Mr Cameron will be setting out a vision of his modern compassionate Conservatism.
But, as he will acknowledge on Wednesday, his party still has a “mountain to climb” to convince voters that it has changed.
How would you help the party in its task? What are the policies, big or small, that the Conservatives should adopt if they are to win the next general election?
What is your big idea for the Conservatives?
And if you’re a lifelong Labour supporter, what one policy would the Tories need to adopt to win your vote?
**Send us your comments using the form below, and we’ll publish a selection here on Wednesday afternoon.**