The vegetarian alternative to gelatin that I often see is agar (which, as I've covered before is not quite the same taste or texture). But! My partner's mum turned me on to this gelatin and agar-free vegetarian jelly mix. Hallelujah.
She used this mix for my welcome to the UK jelly and I honestly couldn't tell the difference. She also very kindly bought me more packets to take back with me. Get ready for some jelly, veggie friends!