No, this looks like sun scald. They've been blasted by the hot sun. Normally tomatoes grow shaded by the leaves, but the crazy heat wave we've been having is too much. I can't stand it myself. The leaves should never be trimmed off. The fruit should be shaded by the leaves, but the leaves need full sun for photosynthesis. Too much rain would be evident by splitting of skin.

what are the leaves like? It could be a sign of tomato blight. especially if you have had it very wet in the last few weeks.

https://www.rhs.org.uk/advice/profile?PID=217

the dark green on cherry toms looks ok but it may be greenback and that is due to weather conditions also.

https://www.rhs.org.uk/advice/profile?PID=392

Thank you Bathgate and Seaburngirl that’s very helpful. I’m afraid I’d already trimmed the leaves back as I always do but I don’t normally get this problem. Any suggestions, maybe I should add some shade of sorts to replace the shade from the leaves. The dark bit on the tomatoes is brown and squidgy

Just keep the tomato plants well watered and fed. They will speedily regenerate new leaves.

Yes we will hopefully they will regenerate new leaves
Thank you once again for your help.