Sounds like a Siskin. Here's a couple of pics to help you ID it.
Male on the left and female on the right.
I'm afraid you can't post videos directly. They have to be uploaded to YouTube or similar and then linked from there.
Thanks TJ, could well be a Siskin , though they were paler than your pics.
Have uploaded my really bad video to YouTube which is only passable in HD setting.
I had a look at your video, David. I'm afraid even at full screen I could barely make out that there was a bird on the feeder let alone see what it was. Sorry.
Can you get a still of it?
Yes sorry TJ , it was hopeless, I'll try and work something out.
In the meantime I'll assume when I think it's a greenfinch it may be a Siskin.
I've got so much to learn about identifying birds!!