David Cameron is to call for rapid changes in the Conservative Party, in his first conference speech as leader.
David Cameron wants the party to change at all levels
He will tell delegates at its spring gathering in Manchester that change must be "faster, wider and deeper".
He will say Britain "desperately needs" a Conservative Party "ready to tackle the big changes" the country faces.
Meanwhile, senior Tory John Gummer has said Mr Cameron should have apologised for calling the UK Independence Party fruitcakes, loonies and closet racists.
Mr Cameron's comments - over which UKIP is demanding an apology - were made during a phone-in on a London radio station.
Former cabinet minister Mr Gummer told BBC Radio 4's Any Questions that quite a few people in UKIP had views "many people would disagree with", but he believed it was now time to move on.
Ahead of Mr Cameron's speech, research for the BBC's Newsnight has suggested the Tories will lose council seats in the local elections.
The Conservatives will drop 4% from their 2004 vote share, scoring only 33% of the vote and lose 75 seats, the research suggests.
Using council by-election results since January, Professor Colin Rallings from Plymouth University says the Liberal Democrats will be up 2%, gaining 190 seats.
According to the professor, Labour will gain 2% in vote share, but still lose 130 seats.
Party chairman Francis Maude played down the research.
He told the BBC News website: "You can do anything with local government statistics."
But he added: "None of us think there are stupendous gains to be made."
In his keynote speech on Saturday, Mr Cameron will say: "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."
He will say that the need to demonstrate real change refers to every aspect of how the party "behaves" - involving the selection of candidates, decisions made in local government and the issues and causes the party chooses to champion.
He will stress: "We can't afford to waste time going slow on changing our party so now is not the time to put our foot on the brake. Now is the time to press on the accelerator."
On Friday, Mr Cameron said that the party had a "huge mountain to climb" in the inner cities.
Key local elections in London and other urban centres are to be held on 4 May and Mr Cameron said he wanted to give people more power over their lives.