Is this Argyranthemum foeniculaceum?

The British have a cultivar called Argyranthemum foeniculaceum 'Royal Haze' that has more of the blue green leaves like your plant than the grey green of A. foeniculaceum. Also if it is in Britain, it might be hardier to CT climate than A. foeniculaceum, which I could only find in California.

I can't answer the ID although it does look like an Argyranthemum of some kind. Just wanted to note, starbookworm, that for cold hardiness, California has colder zones than Britain. Most of the UK is USDA Zone 8 or 9, with a few pockets of 10 and 7.

Thanks so much.