Blair warns Miliband against shift to the left.
Mr Blair said Labour needed to renew its links with business if it wanted to appear credible on economic issues.
He stressed his support for leader Ed Miliband, but warned the party could not indulge in the "politics of protest".
Addressing members of the Progress campaign group Mr Blair tore into Mr Brown's time in office, claiming "we lost the driving rhythm that made us successful".
He said: "I remain unremittingly an advocate of third way, centre ground, progressive politics that came to be called New Labour. From 1997 we were New labour. In June 2007, frankly we stopped. We didn't become Old Labour exactly but we lost the driving rhythm that made us different and successful."
Mr Blair said a "pro-enterprise and business policy that took away from the Tories the mantle of the party of business" as a reasons for his electoral success. "Job creation is a progressive project and you don't create jobs by attacking the businesses that create them," he said.
"Progressives win when they have the courage to be the change-makers. They lose when the public senses that to please themselves, they retreat to where they feel calm, comfortable and small c conservative, echoing the politics of protest but shunning the hard decisions of Government."