I realise I'm slow in replying but I would really highly recommend St Patrick's in Cornwall Rd (nr Waterloo Station). My eldest has just left and my youngest is still there and the staff and methodolgies are top drawer.
Our two year old is in Bermondsey Community Nursery which is in Gainsford Street, Shad Thames close to Tower Bridge. Friendly staff and the children love it. I'm not sure what their minimum age is. The best bit is it is not for profit and so the costs are very reasonable. Telephone them on 020 7407 4601.