1. May be one of the Berberis.
2. Leaves looked like Artemesia, BUT the flowers gave it away - probably ''Chinese ragwort '', or Sinacalia tangutica (tangutica referring to the gold colour)
Thanks for the replies. I hadn't thought about Berberis, good call Tetters. Chinese Ragwort, that sounds ominous. I'll check them both out.
You are right with both plants. Berberis Darwinii and Sinacalia Tangutica which is quite an interesting plant, if a bit thuggish. If you scroll down on the site it's quite an interesting read.