Those thick leaves are a good sign that it's Spanish bluebell. There's also a difference in the way the flowers hang. Have a look on Google to see the difference.
I'd get rid of them. They are invasive, and if there are native bluebells Hyacinthoides non-scripta growing nearby they can hybridise and out-compete the native species. They are not easy to dig out, and the bulb sink deep into the soil. But if you just keep removing the foliage as it appears, and don't let them go to seed, you can control them.
There is some woodland nearby that might have bluebells. They are pretty but I believe they are endangering our native bluebell which is such a shame. I'll prob dig them up, see if I can get some native ones or just replace with snowdrops for next year. Thanks all.
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