It looks like Wire Vine (Muhlenbeckia)

Tug, you're right, and it's an awful thing. Lindalily, look it up and note its common names! I cleared a courtyard garden of it once, three feet deep, and twenty feet up the trees. I could throw myself onto the mat it made and bounce! Get rid. Some suppliers still stock the damn stuff as a good landscaping shrub. If only they knew how invasive and stubborn it is once established.

Thank you Tugbrethil and Worthy1 for your responses, I had been trying for some time to find out its name. Some work ahead I think to remove it!