The process to review all the parliamentary constituency boundaries (such as Walthamstow) in England is now well under way. Here is a link to the first draft of the Boundary Commission proposals, officially due out tomorrow, and this is what they have to say about Walthamstow [on p.11]:
"In Waltham Forest, we noted that the electorate of the borough is such that it could be divided into two constituencies. However, having decided to include Waltham Forest wards in a cross-River Lee constituency, we propose to create a Walthamstow constituency containing ten central Waltham Forest wards, including one (Hale End and Highams Park) from the existing Chingford and Woodford Green constituency and two (Forest and Leytonstone) from the existing Leyton and Wanstead constituency. The four southernmost Waltham Forest wards are included in a Stratford constituency together with five wards from the north west of Newham"
There is now a lengthy consultation process, in the course of which many details may change. The boundaries should be all but fixed by the end of 2012, though the changes are not in effect until the legislation receives the Royal Assent, probably in late 2013.