cucumber and aubergine.

I looked at This and it says Aub's in Jan, Cucumbers in Feb/Mar.

Once cukes sprout, they grow rapidly and need heat which is their native climate. If you can't give them heat right away, they're subject to damping off and cold setback so there's little point starting them early. March is the earliest I'd recommend. Aubergines would be very similar in needs.

after a series of high winds dessimated a few of my squashes, courgettes and (one & only surviving) outdoor cucumber, I got some more seeds and did not sow them till late June - and got a fantastic crop of Marketmore right through to October until the frosts get them.

I'm with Trillium, if your around manchester, march/april is early enough.
 A question for Porffor. When you said late courgettes, did you mean late as in sowing or late as in variety? (or both)