BASILDON and Billericay seat was formed for the 2010 general election, merging the former constituency of Billericay with parts of the former Basildon constituency.
Basildon was famously a Conservative seat throughout the 1980s, until a landslide Labour victory in 1997.
They won the next two elections, until Tory John Baron won  the newly-created Basildon and Billericay seat five years ago.
Mr Baron was first voted into the Conservative-strong Billericay seat in 2001.
His main challenger is now Ukip which took three seats in Billericay at the elections in 2010.

CASTLE POINT
The seat was created in 1983, mostly from the former South East Essex seat, and includes Canvey, Hadleigh, South Benfleet and Thundersley.
All but one General Election since has been won by the Tories.
Labour lifted the seat in the 1997 landslide election when it went on to form the Government. Tory Bob Spink won it back in 2001, but subsequently resigned from the Conservative Party on 22 April 2008. He briefly joined UKIP, but resigned the whip shortly afterwards and sat as an Independent MP. In 2010 Mr Spink lost to incumbent MP Rebecca Harris.
Ukip could figure strongly here again. Nigel Farage announced it as a target he thought they could win when he visited it in May after the party’s success at the local elections.

RAYLEIGH & WICKFORD
The seat was only created by the Fifth Periodic Review of Westminster constituencies in 2007, meaning 2010 is the one and only General Election seen in the Rayleigh and Wickford constituency.
The previous Rayleigh constituency was always a Conservative stronghold.
Mark Francois MP was voted in during the 2001 election with a 50.1 per cent majority, this grew to 55.4 per cent in 2005 and increased even further to 57.8 per cent in 2010.
Labour had traditionally been the second party in the area, polling between 20 and 30 per cent of the vote, until 2010 when the Lib Dems took advantage of Labour’s 12 per cent drop to claim a slim lead.
Polling just 15.1 per cent of the vote though, the competition between the Lib Dems and Labour purely served to strengthen the Tory grip on the seat.

ROCHFORD & SOUTHEND EAST
Rochford and Southend East was created in 1997 and despite Labour coming to power that year it remained Conservative.
It does contain traditional Labour heartlands such as the Kursaal and Victoria wards in Southend, but sitting MP James Duddridge increased his majority five years ago.
Before that, the seat was taken by fellow Conservative Sir Teddy Taylor. A redrawn constituency in 1997 included Rochford.
The closest the Tories have come to being usurped in Southend East and Rochford was in the 1997 election, but the party’s candidate Nigel Smith was still some 4,000 votes from taking the seat.

SOUTH BASILDON & EAST THURROCK
SOUTH Basildon and East Thurrock seat was also newly-created ahead of the 2010 general election, incorporating some parts of the former Basildon constituency.
Tory Stephen Metcalfe was elected, following the trend of the Basildon borough voting for the Conservatives.
The population traditionally migrated from the East End of London, and switched their allegiance from Labour to Tory after coming into money in Essex.
However, Ukip has largely overtaken Labour as the main opposition party, taking 11 seats on Basildon Council in 2014. Ukip had a 39 per cent share of the vote, compared with the Tories’ 35 per cent.

SOUTHEND WEST
The seat, created in 1950, has only ever had three MPs – all Conservative.
Sir Henry Channon was first elected to the seat and he held it until his death in 1958. In the subsequent by-election his son Paul, took the constituency, which he held before retiring in 1997.
Sir David Amess, retained the seat since that year, registering a healthy majority in 2010.
Despite the Tories and Independents holding more seats locally, the biggest challengers to Sir David have been the Lib Dems, who have consistently finished second since the 1990s.

THURROCK
Since the Thurrock seat was created, only twice have Labour not held it. They lost the 1987 election before regaining the seat in 1992, and most crucially they lost five years ago. Both to the Tories.
The 2010 victory for the Conservative’s was a key win – only 0.2 percent was in it – in helping David Cameron into Downing Street.
Ms Doyle-Price and her party are desperate to retain the seat in their bid for another stint in No.10 in what once again looks certain to be a close run election, but the emergence of a third major player in the constituency with a very real chance of victory – Ukip – means this seat cannot be called.