In 1544, Henry VIII granted the town a charter as a port in its own right, separate from Hastings, but it was another 97 years before its right to elect MPs was restored, by a resolution of the Long Parliament on 4 February 1641.
This made it one of the last boroughs to be acquire the right to vote before the Great Reform Act 1832 – only Newark and Durham, enfranchised during the reign of Charles II, came later.
The borough consisted of the parish of Seaford, a small town which had ceased to have much value as a port after the destruction of its harbour by storms at the end of the 16th century.
Indeed, during the 18th century the Duke of Newcastle deliberately restricted the number of voters to those on whose loyalties he could depend, and successfully resisted an election petition in 1761 which would have widened the electorate to include all inhabitants not receiving alms.
After Newcastle's death the Treasury initially gained complete control of Seaford, but the disfranchisement of the customs officers by Crewe's Act in 1782 reduced the electorate to 24,[2] leaving the majority finely balanced.
Throughout the 1780s a struggle for control continued, fought out both through a series of election petitions in the House of Commons and by legal action against the corporation at the quarter sessions.