Elevated and bordering Greater London and Buckinghamshire, this part of Hertfordshire is for its residents mostly middle-class suburbia, an established haven for commuters who travel from the outer reaches of theLondon Underground'sMetropolitan line or two railways from London which serve different parts of the seat: theWest Coast Main Line andAylesbury Line. Much of the constituency is within theGreater London Built-up Area, though it also containsGreen Belt land.
The constituency was formed from theWatford Division of Hertfordshire, excluding the part comprising the Municipal Borough of Watford. It also included the parishes ofAbbots Langley andSarratt, transferred fromHemel Hempstead.
The District of Three Rivers wards of Ashridge, Bedmond, Carpenders Park, Chorleywood, Chorleywood West, Croxley Green, Croxley Green North, Croxley Green South, Hayling, Langleybury, Maple Cross and West Hyde, Mill End, Money Hill, Moor Park, Northwood, Oxhey Hall, Rickmansworth, and Sarratt; and
The District of Dacorum wards of Berkhamsted Central, Berkhamsted East, Berkhamsted West, Bovingdon and Flaunden, Chipperfield, Kings Langley, and Northchurch.[6]
The District of Three Rivers wards of Ashridge, Chorleywood, Chorleywood West, Croxley Green, Croxley Green North, Croxley Green South, Hayling, Maple Cross and West Hyde, Mill End, Money Hill, Moor Park, Northwood, Rickmansworth, and Sarratt; and
The District of Dacorum wards of Aldbury and Wigginton, Berkhamsted Central, Berkhamsted East, Berkhamsted West, Bovingdon and Flaunden, Chipperfield, Northchurch, Tring Central, Tring East, and Tring West.[7]
The District of Three Rivers wards of Chorleywood East, Chorleywood West, Croxley Green, Croxley Green North, Croxley Green South, Hayling, Maple Cross and Mill End, Moor Park and Eastbury, Northwood, Penn, Rickmansworth, Rickmansworth West, and Sarratt; and
The District of Dacorum wards of Aldbury and Wigginton, Berkhamsted Castle, Berkhamsted East, Berkhamsted West, Bovingdon, Flaunden and Chipperfield, Northchurch, Tring Central, Tring East, and Tring West.[8]
Minor gain from Hemel Hempstead following revision of local authority wards.
The constituency saw major changes with the bulk of the portion of the previous iteration of seat in the Borough of Dacorum, including the towns ofBerkhamsted andTring, forming part of the newly created constituency ofHarpenden and Berkhamsted. The Bovingdon, Flaunden and Chipperfield ward went toHemel Hempstead in exchange for theKings Langley ward. The parts of the District of Three Rivers not previously within the constituency were transferred primarily fromWatford, with a small area fromSt Albans. Only 55% of the electorate of the former constituency remained in the redrawn seat, and only 63% of the redrawn seat's electorate came from the previous version of the constituency[10]
^Acounty constituency (for the purposes of election expenses and type of returning officer)
^As with all constituencies, the constituency elects one Member of Parliament (MP) by thefirst past the post system of election at least every five years.
