Apparently there's a switch that detects when you depress your brake pedal which can break, if your brakes are working fine that seems the most likely thing. Here's one on Ebay for £5, I've used the seller although I can't recall what for. I'd check yours first in case it's just come loose or disconnected, not sure where it is but the Ebay picture should help you identify it. 2004 Daihatsu Copen Turbo 659cc Brake Pedal Switch Sensor | eBay
Oh wow. Thanks. You are absolutely correct. I managed to find a workshop that was opened on Sunday and the mechanic fix it for me free.
This type of issue can also happen with the handbrake, but the warning light on the instrument cluster stays on even if the handbrake is released. This can often just be a sticky switch which has had dust and dirt build up as it is never cleaned. This scared Dawn once in one of my other cars as she didn't notice that the light hadn't gone off on the dashboard when she released the handbrake and thought she had brake failure when she was driving as this is when she noticed the warning light was still on!
