I had this problem. I have hopefully fixed it last week. Been fine since. Driven (80 miles ) pulled fuel pump relay out with pliers as it seemed like it was welded in there. All corroded, swapped it for the horn relay put some contact cleaner on it and now ( fingers crossed 🤞
all ok. Relay is located in passengers foot well. Hope you get yours fixed soon. My car is diesel auto. All the best Chris