Hi Kate — Just posted a mix to spray them with which they hate. It is a ‘tea’ made from garlic, nettles, basil or wormwood. As slug hunter says the tomato leaves are loathed by them as well, I would chop up a ton of those too for good measure and add them to the brew.
Apparently the aphids suck the sap from the plant turning it into a sticky gloop which ants love as Charles said. I hope you can get rid of them before the ants locate them.
You could also catch any ladybirds you can find and put them on or near the plants effected. Each ladybird eats up to 400 aphids per day !
Good luck. Do let us know how you get on.
Very best wishes
Julie