Intermittent starting problem.

[Mem]

Over the past 6 months i have been having intermittent problems starting my Subaru Forester. I have foot on brake and press the start button and nothing. The dash says depress brake which i do to no avail. After depressing the brake for some time the car will start. The dealer said it is hard to diagnose because it is intermittent..I have taken it to an auto electrician who has said the same thing..Is anyone else experiencing this problem and if so what did you do..There is nothing wrong with the battery..