In article , Brendy Brendy.1qvmw2@gar
denbanter.co.uk writes

Could you please tell me if this is a weed?

It's a willowherb, in other words a rather invasive british wild flower.

Should I pull them all out?

That's entirely up to you. Small pink flowers, lots of seed, tendency
to spread.
--
Kay
"Do not insult the crocodile until you have crossed the river"