Jenson has won six of the frist seven Grands Prix of 2009, and is keen to extend that record at this weekend's British Grand Prix, stepping closer to the crown with each race.
"The only thing that can go wrong now is they have a really bad run of reliability," explained Mansell to Autosport, "but I don't see that happening.
"He is the best in the business now and that car looks just amazing.
"The great thing is that he had served a very long apprenticeship and now it's coming together," added 'Our Nige', pointing out the similarity between his own career and that of Button. "The thing that is really good for him, and I congratulate him on, is that he is not letting this go, he is staying focused.
"In fact he is more focused than I have ever seen him and better than ever as well."