This Hertfordshire constituency contains the cathedral city of St Albans to the north, and the towns of London Colney and Bricket Wood to the south. It is home to many commuters into London, who can travel both by rail and road.
The constituency is the southern part of the St Albans District & City Council area along with a small portion of Three Rivers council. The Tories are the largest party on the hung council with the Lib Dems second.
After Watford, St Albans is the second-most marginal seat of the 11 in Hertfordshire.
Conservative majority in 2010: 2,252
Based on the 2010 result, this is the Liberal Democrats' best target in the Anglia region
The Lib Dems would need a swing of just 2% to win in 2015 and Labour would need a 12% swing
Anne Main has been the Conservative MP for St Albans since 2005. Labour won the seat in 1997 for the first time since 1945 and Kerry Pollard held it for eight years.
Candidates in 2015
Jack Easton - Green
Anne Main - Conservative
Kerry Pollard - Labour
Sandy Walkington - Liberal Democrats
Chris Wright - UKIP