The seat was created for the February 1974 general election, largely from the majority of the constituency of Maldon, including the towns of Braintree and Witham. It underwent a major redistribution for the 2010 general election when Witham was formed as a separate constituency. This resulted in making the seat safer for the Conservatives.
The former Leader of the House Tony Newton held the seat for the Conservatives from its creation in 1974 until 1997 when Alan Hurst defeated Newton to gain the seat for Labour. Brooks Newmark defeated Hurst in 2005 to regain the seat for the Conservatives, and held it until he stood down in 2015, being succeeded by James Cleverly, also a Conservative.[3]
The Urban Districts of Braintree and Bocking, and Witham;
The Rural District of Braintree; and
The Rural District of Chelmsford civil parishes of Boreham, Broomfield, Chignall, Good Easter, Great and Little Leighs, Great Waltham, Little Waltham, Mashbury, Pleshey, Roxwell, Springfield, and Writtle.[4]
The District of Braintree wards of Black Notley, Bocking North, Bocking South, Braintree Central, Braintree East, Braintree West, Coggeshall, Cressing, Hatfield Peverel, Kelvedon, Panfield, Rayne, Terling, Three Fields, Witham Central, Witham Chipping Hill, Witham North, Witham Silver End and Rivenhall, Witham South, and Witham West; and
The Borough of Chelmsford wards of Broomfield and Chignall, Good Easter Mashbury and Roxwell, Great and Little Leighs and Little Waltham, Great Waltham and Pleshey, and Writtle.[5]
Following changes to the structure of local authorities in 1974, the seat was largely unchanged, with just the Boreham and Springfield ward of Chelmsford Borough being transferred to the Chelmsford constituency.
The District of Braintree wards of Black Notley, Bocking North, Bocking South, Braintree Central, Braintree East, Braintree West, Coggeshall, Cressing, Earls Colne, Gosfield, Hatfield Peveril, Kelvedon, Panfield, Rayne, Terling, Three Fields, Witham Central, Witham Chipping Hill, Witham North, Witham Silver End and Rivenhall, Witham South, and Witham West.[6]
The parts in the Borough of Chelmsford now included in the new constituency of West Chelmsford. Two small wards (Earls Colne and Gosfield) transferred from Saffron Walden.
The District of Braintree wards of Bocking Blackwater, Bocking North, Bocking South, Braintree Central, Braintree East, Braintree South, Bumpstead, Cressing and Stisted, Gosfield and Greenstead Green, Great Notley and Braintree West, Halstead St Andrews, Halstead Trinity, Hedingham and Maplestead, Panfield, Rayne, Stour Valley North, Stour Valley South, The Three Colnes, Three Fields, Upper Colne, and Yeldham.[7]
The 2010 redistribution saw a major change, with southern and western areas, including the town of Witham, forming the basis of the new County Constituency of Witham. Extended northwards, gaining the District of Braintree wards previously in Saffron Walden, including the town of Halstead.
The District of Braintree wards of: Bocking Blackwater; Bocking North; Bocking South; Braintree Central & Beckers Green; Braintree South; Braintree West; Bumpstead; Gosfield & Greenstead Green; Great Notley & Black Notley; Halstead St. Andrew's; Halstead Trinity; Hedingham; Rayne; Stour Valley North; Stour Valley South; Three Fields; Yeldham.
The District of Uttlesford wards of: Felsted & Stebbing; The Sampfords.[8]
Minor changes – the two Uttlesford District wards were transferred from Saffron Walden (renamed North West Essex), offset by a net loss to Witham mainly due to revision of ward boundaries.