Thanks folks,
I dont think these are your common wasp. They are over an inch long and completely black apart from two yellow rings around their body. They are not aggressive, I have approached them quite closely and am still alive to tell the tale! Would still prefer to move them on. Have sprayed the ground with bleach, filled what holes I can see with sand and they still keep coming back. Just hovering around an area about 6 square metres, landing occassionally and flying around again.