I find it a fascinating theme and have a lot to learn about it...
This document (from the Economic History Society) has a graph (page 3) that shows around 35% of housing was local authority rented in 1961 in the north of the current Borough of Southwark (the pre-1965 boundary of the borough, and so including the Elephant and Walworth, but excluding the Boroughs of Camberwell and Bermondsey), and that this rose to 75% in 1981.
Meanwhile until 1981 owner occupancy was almost non-existent in this area until 1991. Over the period 1961 - 1981, private rented housing almost disappeared, dropping from 65% to 10% of housing - replaced largely by council rented accommodation and later some Housing Association rented accommodation.
This interesting document by local historian Stephen Humphrey (he has a new book out on the subject) he suggests "The bombing of Walworth in the Second World War was severe, but paradoxically the great majority of old buildings survived. Small areas suffered disproportionately, such as the Elephant and Castle, where many buildings were totally destroyed, but for the rest, they usually lost their windows and maybe suffered further minor damage."
Wikpedia (where else) shows Labour have held Walworth consistently since 1964, with the exceptions of LibDems/NOC 2002-2006 and LibDems 2006-2010.
So certainly Labour were in power during the period Walworth was massively redeveloped, but to say redevelopment was simply a ruse to stop gentrification sounds tendentious to me (it would be enlightening to look at local newspapers of the day!) - and it would certainly be diametrically opposite to the policies of the current Labour group who are explicitly promoting gentrification (or is that "mixed communities"?) at the Elephant at any price.
In any event it is certain that the redevelopment/"slum clearance" in Walworth provided rich pickings for lawyers involved in the compulsory purchase process in the 1960s and 1970s...