The parliamentary constituency of Westbury dated back to the 15th century but the name was abandoned in 2010, when the town and most of the former constituency became part of the new South West Wiltshire constituency. Before the parliamentary reforms of the mid-19th century, Westbury was considered a pocket borough, at one point having as few as twenty-four electors. This status led to gifts to the town from the owners of the parliamentary borough, including the former town hall in the Market Place, donated by Sir Manasseh Masseh Lopes.