Big Green Caterpillar

Earlier today I put a load of tomato leaves into the recycling bin, and then later I found a big green caterpillar inside the lid.  It's about 2.5cm long, very fat, big green eyes, and has diagonal markings with a spine at the back. 

Does anyone have any suggestions what it might be?  I found links online that showed tomato hornworm, and it looks very similar, but most of the links are from North America.  Do we have tomato hornworm in the UK?

Sounds like a tomato hornworm. They're everywhere. I used to get them in Australia.

The strange thing is, the tomato plants don't seem to be damaged.  My neighbour's plants however have been really bad this year, she's been thinking the devastation was due to blight, but I'm now wondering if the big fat caterpillar has crawled over the fence having stuffed itself in her greenhouse and he's now discovered a fresh supply of his favourite food!

He's so big I don't have the heart (or stomach) to squash him - at the moment I have him in a box with a selection of leaves! Though he may go back into the recycling bin ready for collection tomorrow.

IME they don't eat the leaves, but they feast on the tomatoes!

Is this the critter you're looking at, jancee?

That's a hornworm. They actually do eat foliage but the big damage they do is to the fruit:

You were lucky you found him before he pulled out his knife and fork, uncorked a Caterpillar Merlot, tucked his serviette into his collar, and tucked in.

Yes, he looks like that, but not quite so large - maybe a teenager, stopped in his tracks!  I'll double check all the fruit in the morning.  Had been feeling quite smug that my tomatoes were better than Monty's!