If its been outside all winter, it may have died - these are frost tender. However, you've asked why it hasn't flowered, which implies there are leaves - how did you treat it after flowering last year? Did you feed it or cut the leaves?

Thanks for reply,we live in the south of France and have found that our plants are hardy and have ,untill this year have flowered,after flowering we let them rest and then remove dead heads and odd leaves as they die,thats it,we have never fed them,look forward to more advice Allen

If its got leaves currently, feed it weekly with a balanced liquid feed until the leaves disappear.

Mine have flower buds but are not ready to flower just yet.

If they are extremely crowded, you also may want to dig them up and separate them after the leaves dissappear. Scilla peruviana can also take a long time to bloom in the spring. Mine have sometimes waited until May.