Jenson Button fears the careers of several Formula One drivers could be on the line if new weight rules are not introduced next season.
The sport operates by a strict weight code that at present means car and driver, in overalls, should be no more than 642kg.
With the introduction of new powertrain regulations from 2014, motor sport’s world governing body the FIA, has increased the weight limit to 692kg.
The complexity of the new technology, with 1.6-litre V6 turbo-charged engines replacing the current 2.4-litre V8s and energy recovery systems (ERS) being introduced alongside kinetic energy recovery systems (KERS), means the teams are struggling to hit the new target.
One driver seemingly in trouble is Nico Hulkenberg, with the German on the lookout for a new drive as he will be leaving Sauber at the end of the year.
Weighing in at 78kg, Hulkenberg is understood to be one of the heaviest drivers on the grid.
Red Bull team principal Christian Horner has confirmed if Hulkenberg had been in contention for the seat to be vacated by Mark Webber, he would have had serious concerns about accommodating the 26-year-old.
At 74kg, Button has revealed he is already on the current limit, and is acutely aware of the difficulties McLaren face next term to ensure he and his car do not breach the rules.
“I’ve struggled to make the weight limit for the last three years,” said Button. “I love fitness training, but there is certain training I have to do, and parts of my training I can’t do. I can’t build muscle and I can’t eat carbohydrates because I have to be a set weight, and it’s going to get worse next year as well.
“We don’t know how bad it’s going to be, but it’s going to be very tricky. Every year we start with ballast, and throughout the year, because you add parts to the car, the car puts more weight on.
“Whereas at the start of next year, every team won’t have ballast on the car (due to the new rules) and it’s going to get worse through the season.
“It does hurt the heavier driver, and it’s very unfair to say ‘lose weight’ because some of us can’t lose any more.
“You need to have skin on your bones, and a little bit of muscle to drive a Formula One car, so it is unfair.”