I think it might be Polygonum baldschuanicum.

if they are the flowers of it then it doesn't look like it. but the foliage certainly does.

Polygonum baldschuanicum is the Russian vine/mile a minute but the flowers aren't right for it either.

Oh dear, not liking the sound of this ! I’ve been meaning to clear that border out for a while now and improve the soil as plants are getting a bit congested, think I need to get on with the job!

Bit hard to see, but that could well be Enchanter's Nightshade. Circaea lutetiana.
We got a lot of it at our last garden. At least it is very easy to pull out, if that is what it is.
Closer image of leaf and flower would help, if possible.

Well, in my garden there is nothing worse than bindweed and it certainly isn't that. Good luck in digging it up!

The weather is really bad here at the moment , I will get a better picture as soon as it clears up .

Its not enchanters nightshade as the leaf is wrong. I have lots in one of my shady borders. and it is a beggar to get out due to its brittle rhizomes.

Well Andrea, whatever it is you don't want it....hope it hasn't seeded yet!

I contacted the RHS advice line and emailed them some photos, and for information this was their reply :

“This plant appears to be Fallopia convolvulus, commonly known as the black bindweed. It is a common annual weed of waste grounds and is easily dispersed by seed.“

Now I just have to try eradicate it !

good I have been puzzling over this and at least it is an annual .

I knew I had seen it somewhere before. We had it in our last garden. My memory is not what it used to be.
At least it is an annual so stopping it before it sets seed will eventually get rid of it. That of course depends on how persistent the seeds are from ones already dropped.

Thanks for all your input 👍🏼