Former Conservative leadership hopeful Michael Portillo has warned that some people in David Cameron's shadow cabinet look like a "throwback".
Mr Portillo: Ex-Tory leader hopeful
Mr Portillo, who quit as an MP at the last election, said the Tory leader had to "smash the pigeon hole" his party had been in since the Thatcher years.
"It is not just David Cameron who has to look different," Mr Portillo said.
This weekend Mr Cameron wrapped up his first Tory conference as leader with a call for rapid and deep change.
He told the Conservative Spring gathering in Manchester that Britain "desperately" needed a Conservative Party "ready to tackle the big changes" the country faces.
Mr Cameron's speech came just a day after research for the BBC's Newsnight suggested the Tories will lose council seats in the local elections on 4 May.
New and fresh?
Mr Portillo told BBC Radio 4's Today programme he did not entirely believe that the honeymoon was over for Mr Cameron.
He said he backed the new Conservative leader's programme for change - the word that emblazoned banners at the conference.
The former defence secretary said: "I believe the change idea is entirely the right one. The only doubt I have is whether he has yet done enough to convince the public.
"I am not so worried about whether the party likes change or not. The important thing is that the public should see change is really occurring - one of the difficulties he has got is that the team in the shadow cabinet contains a lot of people who are from the party's past.
"And so while David Cameron in his visual images riding on a bicycle, for example, clearly represents something new and fresh and changed, the other people who are out there putting out the message look like more of a throwback to former periods."
He added: "People have formed an impression of the Conservatives over a generation, really since Margaret Thatcher came to power, and what David Cameron is trying to do is smash the pigeon hole in which the Tories have been locked since that time."
In his keynote speech on Saturday, Mr Cameron said: "I know some of you think we have had quite enough change for the time being - that now is the time to pause, perhaps to reflect. Time to take it easy.
"Well I say Britain can't wait while we take it easy. This change in our party has to get faster, it must go wider and deeper.
"It is not enough for the leader to change, we will have to change and we must show that the change is real, that it is lasting."