I know this is a long shot but it looks like Asiatic Lilies. Keep them going. This is the fun of gardening. I would move them to a sunny location and see what you get.

I think Fritillaria imperialis, the Imperial Fritillaria. They are coming through the groun now an look like this.

Could be either. Does the foliage have a slightly unpleasant [foxy] smell? if yes it is Fritillaria imperialis.
If no could well be a lily. Some of mine are showing growth and they do look similar.

The plants continue doing well, but so far no particular smell from the foliage. I seem to think these were given to us last year as suitable either for indoors our outdoors. If I'm thinking of the same thing, we kept them (in flower) in the conservatory for a while but decided to put them out when an unpleasant smell developed. Being unsure how they would cope over winter I cut them down when they were looking dead or dying and brought them in, not knowing what to expect, with the results you see in my photo. I guess I must simply wait for flowers and try again to identify from them. Thanks for the suggestions. Alan.

if they don't have an unpleasant smell then I think lilies. You would certainly smell them if the were frits.

Many thanks again. When there is only foliage to go by, it's always likely to be hard to be sure. Anyway, we'll see what happens and, if I remember(!), I'll post again when flowers develop.