Every few years, the map of Parliamentary constituencies is revised, to ensure that, as the population changes, all MPs continue to represent broadly similar numbers of voters. The latest review is now near completion. The new electoral map in the East redraws parts of all six counties and, because we are a fast growing region, we will acquire three new constituencies.
How does the review work?
The review is carried out by the independent Boundary Commission under rules set by Parliament. Their task was to produce a map which keeps 650 constituencies, with each one including approximately the same number of registered electors (around 75,000). The Commission considers natural boundaries, historic links and communication routes, as far as possible they try to match local government boundaries, but they do not consider political impact.
The Commission produces a preliminary map which is then put out to consultation with the public and interested parties, including political parties and local authorities. So far, there have been two rounds of consultation, with 45,000 comments submitted, and half the original proposals have been modified. All the comments are publicly available on the Commission’s website.
The third, and final, round of consultation closes on 5 December. The Commission will then make any further revisions and submit the final map to the Speaker of the House of Commons by 1 July 2023. Parliament cannot amend the proposals, and the Speaker must make an Order in Council to implement the plan, for the King’s approval within 4 months. The changes take effect from the date when the Order is signed and will be used at any subsequent byelections or general elections.
Changes in the East of England
Because the English population is growing faster than the rest of the UK, the new electoral map will have 10 more constituencies in England. As a rapidly growing region, the number of constituencies in the East will increase, from 58 to 61.
The new map has two constituencies which cross county boundaries. Five constituencies are unchanged, 42 have minor changes and 5 have new names to reflect local preferences.
This leaves 14 constituencies where the changes affect more than 20% of the current electorate:
Hertfordshire and Bedfordshire (+1 constituency)
Hitchin is a new constituency, crossing the border between Bedfordshire and Hertfordshire. The current Hitchin and Harpenden constituency is split. The northern half becomes the new Hitchin constituency, with additional wards transferred from Mid Bedfordshire and North Bedfordshire. The Southern half joins a third of Hertfordshire South West, and some wards from Hemel Hempstead to form a new Harpenden and Berkhamstead constituency.
Hertfordshire South West adds wards from Watford, Hemel Hempstead and a few from St Albans.
Watford loses a quarter of its current electors and adds some from Hertsmere.
Suffolk and Norfolk (+1)
The first proposals created a new constituency crossing the Suffolk/Essex border, but this was abandoned after opposition during the consultation. Instead, to keep constituencies within the size limit, there is now a new constituency, Waveney Valley, which crosses the Suffolk/Norfolk border. This combines the rural parts of the current Waveney constituency with parts of Suffolk Central & Ipswich, and Bury St Edmunds, which is compensated by adding some wards from Suffolk West.
This leaves the urban area of Waveney to form a new, largely urban, constituency of Lowestoft, much more similar to its neighbour, Great Yarmouth, than the previous mixed constituency.
Cambridgeshire (+1)
This countyis the most substantially changed. At present Cambridge itself is surrounded by four large constituencies. Cambridgeshire North West loses some wards, but there are major changes to the south and west. There, the new map has four constituencies:
St Neots & Mid-Cambridgeshire is a new constituency to the West, formed from parts of Huntingdon, South Cambridgeshire and South East Cambridgeshire.
Cambridgeshire East is a new constituency, adding two thirds of Cambridgeshire South East to parts of Cambridgeshire North East and Cambridgeshire South.
Cambridgeshire South adds parts of South East Cambridgeshire, and a small part of Cambridge to the current constituency
Huntingdon loses a third of its electors to St Neots & Mid-Cambridgeshire, and addsa third of Cambridgeshire South
Essex
Wards are exchanged between two constituencies. Rochford and Southend East and Southend West, which is renamed Southend Central & Leigh.
Colchester, loses 9% of its electors to Harwich and North Essex.
Political impact
The national effect of the boundary changes is to move seats from the North of England and Wales into the South and East. Electoral Calculus estimates that the national political effect is to create 13 more Conservative seats, while Labour lose 2, and LibDems 1.
Because almost all the seats in the Eastern region are currently held by Conservatives, most of the boundary changes in the East are unlikely, of themselves, to change the political position of the parties. However, for the last year, all polls have suggested that Conservatives are likely to lose a significant number of seats, including a number in the East.
To win a Parliamentary majority, on an even swing, Labour would need to take at least nine seats from the Conservatives in this region. Five of these will have no, or very minor, changes. Three of them – Watford, Colchester, and Rochford & Southend East – have more significant change.
The Cambridgeshire position is the least clear. Both the southern Cambridgeshire seats are Liberal Democrat targets. In the 2019 general election, LibDems came second in both Cambridgeshire South (with 42% of the vote) and Cambridgeshire South East (with 32%). In the South, the LibDems control the Council, but they will lose a third of their voters to the new St Neots constituency, to be replaced by voters from Cambridgeshire South East, and a smaller number from Cambridge itself. However, the Electoral Calculus polling suggests that the balance between the LibDems and Labour in these two constituencies may have changed.
Projections
Electoral Calculus estimates the effects of the new boundaries by constituency. It calculates an “implied majority” (the likely majority based on figures from the 2019 election). It also uses current MRP polling to estimate the probability of each party winning the seat under the new boundaries (if an election were to be held today).
The table shows the results for the constituencies which will undergo significant change. In every one, Labour is the challenger to the Conservatives. They are listed with the most likely Labour win first.
| New constituency | Con majority (2019 votes) | Current probability of Labour win | Current probability of Conservative win | Current probability of LibDem win |
| Watford | 2,872 | 97% | 3% | 0% |
| Colchester | 9.558 | 88% | 12% | 0% |
| Southend Central & Leigh | 11,068 | 85% | 15% | 0% |
| Lowestoft | 15,704 | 78% | 22% | 0% |
| Hitchin | 14,219 | 76% | 24% | 1% |
| St.Neots & Mid Cambridgeshire | 13,842 | 68% | 29% | 3% |
| Rochford & Southend East | 16,363 | 60% | 40% | 0% |
| Hertfordshire South West | 17,487 | 58% | 42% | 0% |
| Waveney Valley | 20,626 | 55% | 45% | 0% |
| Cambridgeshire South | 2,074 | 52% | 22% | 25% |
| Cambridgeshire East | 13,310 | 50% | 43% | 7% |
| Harpenden & Berkhamstead | 14,145 | 43% | 52% | 5% |
The third, and final round of consultation on the proposals is now open. Submissions must be made by 5th December.
The full report of the consultation explains in detail the decisions made in response to comments. A map of the proposed new boundaries is also available online.
