PL-L, metal halide, and SON lamps will be phased out.
https://www.sparksdirect.co.uk/blog/flu ... ember-2023

This is not quite as extreme as it sounds. The phase out relates to a desire to restrict the supply of lamps on the market containing mercury, and of course fluorescent based lighting typically has a relatively high mercury content. The impacts on metal halide lighting will be greater than on SON, and it would certainly remain possible for SON to remain in production if it is mercury-free (which does exist), though certainly the range of products available would be massively diminished and become more expensive to produce and sell.

The details are best currently viewed here on the gov.uk website.