David Cameron defended the coalition's "impressive" £6.2 billion spending cuts today, insisting they show the Government is "getting to grips" with the deficit.
But the Prime Minister conceded that not all the immediate efficiencies he had envisaged in opposition had been possible.
Interviewed on BBC Radio 4's Today programme, Mr Cameron said: "I think it is quite impressive actually to have a spending round effectively carried out in the first two weeks of the Government and announced and put in place."
He went on: "Before the election obviously we looked at things like ID projects, but until you form the Government you cannot actually see how many ID projects you can scale back.
"Until you are actually in charge of the ship you cannot actually see what the penalty clauses are and what contracts have been signed up to.
"But the key thing is we promised £6 billion of spending reductions and we have delivered £6 billion of spending reductions.
"That is good for our economy. It shows us getting to grips with the deficit. It will enhance international confidence in the economy."
The premier also hit out at the "appalling" financial legacy left by the former Labour administration.
Mr Cameron insisted the austerity measures being introduced by the Government were in line with efforts by other countries to deal with the economic crisis.
"If you look at the threats to the eurozone and the threats to our economy around the world, excessive budget deficits are a big part of the problem and you can see Britain now is part of the mainstream: tackling its deficit, making reductions in year, this year, showing boldness and vision in doing so and rightly getting confidence back in our economy by taking that action."
The Prime Minister defended his shock move to change the rules of the influential 1922 Committee of Tory MPs to include membership for ministers and whips as well as backbenchers.
Efforts to secure the "payroll vote" a say in the election of the body's officials were abandoned however amid an angry revolt over what were seen as efforts to neuter the committee's voice.
Mr Cameron's attempted intervention was seen as a factor in the election last night of Altrincham and Sale MP Graham Brady as the new chairman of the '22, who easily saw off the challenge of Richard Ottaway.
The leadership was believed to have favoured Mr Ottaway for the important role, amid speculation that Mr Brady could become a focus for discontent over the coalition deal with the Liberal Democrats.
Mr Cameron denied trying to suppress backbench opinion.
"If you know my backbenchers, you know they are never going to be supine, and nor should they be," he said.
"In a coalition, in government, clearly it is going to take a lot more work, a lot more conversation, a lot more discussions and that, actually, is something I welcome."
He conceded he had been "quite forceful" sometimes in his efforts to force through modernisation of the party since becoming leader in 2005.
"I recognise, in this parliament with a coalition, you have got to take people with you, you have to discuss and debate," he said.
"We are beginning to demonstrate it is not a lower common denominator coalition. We are getting things done for the good of the country, in the national interest.
"But as we do that, we have got to make sure we take both of our parties with us into what is a very difficult and challenging time for the country.Reuse content