Both contenders vied for the votes of Conservative activists in the south of England at the start of a week in which the 300,000 party members receive ballot papers through the post.
David Cameron's youthful appeal to non-Tory voters has made him the bookies' favourite. Meeting Tory activists in Hampshire yesterday, he and campaign manager, George Osborne, emphasised that appeal.
Mr Davis countered by saying he would keep the politics of Margaret Thatcher alive. Today he will present himself as the champion of the rights of local activists against interference from the centre.
The battle for votes is so intense that Mr Davis, who is shadow Home Secretary, handed the job of negotiating with the Government over the Terrorism Bill to a frontbench colleague, Dominic Grieve, to spend two days whipping up support.
Yesterday he was in Kent, where he met Tory party members, and visited a youth project in Chatham. Today he will be in Essex, Suffolk and Norfolk. He will promise that, if he were leader, there would be no repeat of the incident when Michael Howard sacked an MP, Howard Flight, against local party wishes, for departing from official policy. "Under my leadership, MPs will have the freedom to speak out - and be treated like grown-ups," he will say.
Mr Cameron made a flying visit to meet Tories from Bournemouth, Fareham and Poole yesterday. He told them: "There are millions of people in Britain who share Conservative values but who have not been voting for the Conservative Party and our challenge is to win their support.
"That is why I have argued that we need a positive and optimistic message of change which speaks to people's hopes rather than their fears and which reaches out to those people whose support we need - especially women and younger voters."
Today, Mr Cameron sets out his "compassionate Conservatism'' in a speech to a Tory think-tank, the Centre for Policy Studies. He will propose scrapping the "five barriers to wealth creation" - irresponsible government spending, excessive regulation, EU bureaucracy, inadequate infrastructure, and "insufficient capacity" for developing the nation's talents.