If they,re in a smallish pot, say about 8", then if you,re not putting them in the ground, either in a greenhouse border, or outside, then I would say repot into a pot about 12" wide and 15-18" deep, they probably haven,t been repotted very much, and they are heavy feeders, so the compost will probably have run out of nutrients.
Derek

Agree with Derek and suggest these tomato plants are going to need a lot of tlc!

great advice. will take the risk then and get some new compost!!!

Unless its really warm I,d keep them in the greenhouse the'll do much better
If they are cordons the'll need staking and them or bush variety will need tomato feed as soon as the first truss sets

great pam. dont have greenhouse but patio gets a lot of sun!
have bought tomato feed

Try..(.if possible with this awful weather) to keep them out of the cold wind and nice and warm but not too hot...if we ever get that this year.......and I hope you get some lovely tomatoes

got loads of lovely tomatoes thanks everyone, they're still coming!

Well done, Derek.

Well doneTricia. \0/ \0/ \0/

thanks! tomato and basil salad anyone?

Yes please :-)