Perhaps Lonicera nitida

Lonicera pileata?

Here is a link that might be useful: Box-leaved honeysuckle

Several cultivars of L nitida are widely available here. Baggesens Gold is one very common yellow.

The plants do flower but since they are frequently trimmed and the flowers are very small and a similar colour to the leaves you may not have seen them.

This post was edited by floral_uk on Sun, May 4, 14 at 8:56

Thank you Floral uk, I think you are right with Baggesons Gold. I was thrown by the fact that I have never seen flowers or berries but of course as you say that will probably be because the bush is being constantly trimmed throughout the year.Thanks again for your help.