However, Tony Blair accepts that people need to be shown 'clearly and demonstrably' that things are improving to make sure support for investment continues.
He then told delegates at the '21st Century Public Services - Putting People First' event that change was essential to secure public services for the future.
'The reason I am passionate about change in public services, making changes that are difficult and challenging, including learning from business and the voluntary sector, where it is sensible, is because I believe in public services...
'I know that if having put in this extra money we can't show clearly and demonstrably that the service has got radically better then the consent from the public for investment is in jeopardy. That is why change is not about attacking public services but saving and inspiring them.'
The conference, attended by civil servants and public sector workers, was the idea of the PM and Cabinet secretary Gus O'Donnell.
The PM went on:
'Patients, whatever their wealth; pupils, whatever their background; citizens whatever part of town they live in, (should) get a decent service delivered in the way the 21st century expects.'
Other speakers during the day include chancellor Gordon Brown and Cabinet ministers John Hutton and Patricia Hewitt.