the next redistribution, which came into effect for the February 1974 general election, the constituency was redesignated as a Borough Constituency, composed of the local authorities which had comprised the Soke, together with the small Rural District of Thorney, which was transferred from the administrative county/county constituency of Isle of Ely. The parts in Northamptonshire were transferred to the county constituency of Wellingborough. Meanwhile, as a result of the Local Government Act 1972, the two counties of Huntingdon and Peterborough and Cambridgeshire and Isle of Ely were merged to form the non-metropolitan county of Cambridgeshire, with effect from 1 April 1974. However, the next redistribution did not come into effect until the 1983 general election, when areas to the south of the River Nene, including Fletton and the Ortons, which were now part of the expanded City of Peterborough, were transferred from the abolished County Constituency of Huntingdonshire. Mainly rural areas to the east (Thorney and Eye) and west (Barnack and Werrington) were transferred respectively to the new County Constituencies of North East Cambridgeshire and Huntingdon. The next redistribution, which came into effect for the 1997 general election, saw the creation of the County Constituency of North West Cambridgeshire, which took the areas to the south of the River Nene (City of Peterborough wards of Fletton, Orton Longueville, Orton Waterville and Stanground). Werrington was transferred back from the Huntingdon constituency. Following their review of parliamentary representation in Cambridgeshire in 2005, the Boundary Commission for England made minor alterations to the existing constituencies to deal with population changes, including the transfer back of Thorney and Eye from North East Cambridgeshire. There were also marginal changes to take account of the redistribution of City of Peterborough wards. These changes increased the electorate from 64,893 to 70,640. On the enumeration date of 17 February 2000, the electoral quota for England was 69,934 voters per constituency. The current constituency is composed of built-up areas of Peterborough to the north of the River Nene, as well as rural areas to the east and north and comprises approximately 60% of the electorate of the local authority of the City of Peterborough. Remaining parts of the city, composed of residential areas to the south of the River Nene and rural areas to the west of Peterborough (wards of Barnack, Fletton, Glinton and Wittering, Northborough, Orton Longueville, Orton Waterville, Orton with Hampton, Stanground Central, and Stanground East) form