Also a Giant Defy would also be a good shout as an entry level bike. Normally Giant are better spec for the same money then some think like a Specialized or Trek
This one is small and in Hove...
On that budget it is difficult, but halfords start their Carrera range about starting £250. I bought a bike for my daughter a carrrea subway for her commute to college, once my husband who is a bike machinic, tighten the things the shop forgot, he and I was impressed with the spec for the money...