Conservative leadership contenders David Cameron and David Davis have clashed following the start of a nationwide series of hustings.
The contenders face a long series of hustings
Mr Davis said Mr Cameron's strategy was "like the early Blair", which was "ironic" as the public was "rather sick" of the prime minister.
But Mr Cameron said this was "wrong" and that his differences with Mr Blair were "too many to mention".
The winner of the leadership contest will be announced on 6 December.
Following the first hustings, in Leicester, on Monday, Mr Davis told BBC Radio 4's The World at One: "Our argument today in the hall was that it would be rather ironic if we started to try Blair's approach at the time when the public at large are getting rather sick of it."
The "collective view" was he had won the debate, he said, adding that voters would prefer his "principled politics".
Mr Cameron later told Radio 4's PM programme that "people will say those things and you just have to be relaxed about it.
"I've set out a very clear programme of modern, compassionate conservatism for the Conservative party.
"I've been consistent about the need for the party to change to get back into the cities, to attract young people, to win back women voters."
Mr Cameron is the bookmakers' favourite to win the contest. On Sunday he received the backing of former party leader William Hague.
But Mr Davis said voting among Tory members so far had been slow, adding: "A large number of people haven't made up their minds."
MP Anne Main, a convert from Mr Davis to his rival, said Mr Cameron would "surround himself with an excellent team", if he became leader, which in turn would create policies of "substance".
Mr Cameron's team was showing a "slightly more modern approach, a softer approach", she said.
These could "appeal to a broader base than some of the language and marketing techniques used by the Davis team", she added.
Party members have until 5 December to cast their vote.
There will be 11 hustings events, with the debates held in many different regions of England, as well as one in Scotland and another in Wales.
The last leadership hopeful to be eliminated, Liam Fox, has backed Mr Cameron over David Davis, although he told the Sunday Times it was a "close call".