Crikey. That doesn’t look happy. I’m growing the same variety from the same source and they’re nothing like that. I think it is mosaic virus and the plant needs to go.

Yeah, I'd get rid of that plant. From the terminology used I assume you are in the UK? If you were in the US I'd say plant new seeds in a new garden location for a harvest later this year. I don't how much time is left to grow summer crops over there though (or rather, if you will still have the warmth needed in a couple months time).

Rodney

Sowing new seeds is worth a try, especially if you can provide a cloche. If it were me I’d start them inside to hurry them up. Or you might be able to still find a plant at a garden centre although very unlikely this cultivar.