Electronic fault??

My Renault Megane 1.6 Coupe Cabriolet 05 plate won't start. When attempting to start it the dash says electronic fault. Also the battery light and oil light comes on as well as the "stop" light. Engine doesn't even get to trying to ignite.

Also the brake pedal feels firmer than usual - can't be pushed right down even before attempting to start. Got it started once but it cut out due to 'electronic fault'!

We have had a lot of snow but I don't think that is the cause of all this stress!!
Any ideas what parts might be not working, or any solutions to the problems?