Renault Megane often not starting when button pressed

[Doonhamer]

My dads 4 year old diesel Megane is erratic to start. He inserts the card and it asks to press the brake or clutch and press the start button, but when he does this nothing happens. It's the same with both cards and the batteries have been changed. Eventually it does start after numerous attempts. Seems quite random, sometimes it starts first time and other times it takes 5 minutes of repeatedly inserting cards and pressing the pedals and button. It does always detect the card because the instructions come on the screen every time.


Any ideas? Could it just be the button?