On Wed, 22 Aug 2012 09:36:49 +0100, David Hearn wrote:

when trying to do up the compression joint, I cannot stop the connector
turning before the olive is compressed - even using a pump wrench on
the lugs at the back.

Surprised, compression is normally just hand tight plus 1/2 to 3/4 of a
turn. As others have pointed out have you lubricated the olive/threads,
I'd use a smear of Boss Green rather than silcone grease or PTFE tape.

--
Cheers
Dave.