In an interview with Bloomberg Markets magazine published today, the former prime minister and three time election winner, said he would have been able to win more seats than Brown had.
In 2010 the Conservative Party won 306 seats to Labour's 258. Cameron fell short of an overall majority and was forced into a coalition with the Liberal Democrats.
Blair thinks he could have done better than Brown. "Frankly, if I’d had a fourth election, I would have given Cameron a run for his money,” he said. "I’m not saying I would have won, but it would have been tighter than it was."
In the interview Blair also defends his accumulation of wealth - Bloomberg estimates his companies have taken in £59m since he left office in 2007.
"It genuinely is about making a difference in the world and not about making money," Blair said. "The motivation is not the accumulation of personal wealth. If I’d wanted to do that, I could do it a lot simpler with a lot less time."
Related on HuffPost: