[cc]

Some plants look deformed.
Sweet peppers and Lettuce. 2 Tomatoes looking all right one might be struggling. 
The ones that are dieing are sticky and have tiny white worm like creatures on. Green fly also in greenhouse.  I don't think they are the problem.  They were mainly on potatoes which I have moved outside.
It looks bad if they are going to wipe out everything?

[Goosegirl]

They sound like aphids, so give them a spray with an insecticide which Mods will give some advice as what to use. 

[cc]

Thanks
Mods helppppp

[mumofstig]

RHS always has good advice on what you can use, for what - the link is here
https://www.rhs.org.uk/advice/profile?pid=181