But rents in poorer boroughs such as Bexley, Lewisham and Redbridge continued to rise by up to 2.6 per cent over the summer. The figures, collated by property website Gumtree from data in its adverts, suggest cash-strapped tenants are looking for cheaper rents in less salubrious areas and pushing up prices. The Rental Index shows the high-end rental market across Britain has suffered during the credit crunch.