it could be a campanula but not sure. do you have a picture of it from last year with a flower?

Thanks Seaburngirl for answering.
I've moved things around and I think I had a Lobelia in that pot, I've had suggestions of London Pride (which I don't think I've ever bought) or Begonia which I did have but indoors. I'm getting old and forgetful so will have to keep better notes ?. Guess I will have to wait and see ! T

Can't help with the plant but do remove that Hairy Bittercress before the seeds drop of you'll never get rid of it.

Lobelia is a strong possibility especially if it isQueen Victorial etc.