Jenson Button hits back at former Renault boss Flavio Briatore

Formula One champion Jenson Button has hit back at former Renault boss Flavio Briatore's claim that he is not one of the world's top five drivers.

"It did make me laugh when I read what Flavio said. He likes to be outspoken, but I am very happy. I have done everything I set out to do when I started racing in F1. I am leading the championship and he is not even in the sport," he said.

"I am sat here as the world champion, I've won two races this year, I'm all right. It doesn't upset me - he has got to try a bit harder than that. But I don't know what he was thinking as I thought we got on all right," The Sun quoted Button, as saying.

Button, 30, had two difficult years when Briatore, who is out of the sport after fixing the 2008 Singapore Grand Prix, was his Benetton/Renault boss in 2001-02.

But Button reckons that the bad times have made him a better driver.

"It was the roughest time of my career but it was a learning curve. They are important years and some of us go through more than others. That was a tough time in my career but I wouldn't change it. You need the bad days to make you realise it is not always a walk in the park," he said.

Button unveiled a plaque on champions' avenue at the Circuit de Catalunya yesterday commemorating his title triumph with Brawn GP last year, and  said he is not feeling any pressure despite the stunning start with his new team.