The Octennial Act, an act of the Parliament of Ireland which sets a maximum duration of eight years for the Irish House of Commons, receives royal assent on February 16, 1768. Before this, a dissolution of parliament is not required except on the demise of the Crown, and the previous three general elections were held in 1715, 1727, and 1761, on the respective deaths of Anne, George I, and George II. After the act, general elections are held in 1769, 1776, 1783, 1790, and 1798.
Limiting the duration of parliament is a prime objective of the Irish Patriot Party. Heads of bills are brought, by Charles Lucas in 1761 and 1763 and by Henry Flood in 1765, to limit parliament to seven years as the Septennial Act 1716 does for the Parliament of Great Britain. The heads are rejected by the Privy Council of Great Britain, which, under Poynings’ Law, has to pre-approve any bill before it is formally introduced in the Irish parliament.
Since the end of the Seven Years’ War in 1763, the British government has wished to increase the size of Irish regiments, the part of the British Army charged on the Irish exchequer rather than the British. In 1767, the Chatham Ministry appoints George Townshend, 4th Viscount Townshend, as Lord Lieutenant of Ireland and instructs him to secure the support of the Irish parliament for an Augmentation Bill to effect this increase. The British consider several possible concessions to win over the Irish Patriot Party, and at his speech from the throne, Townshend promises judicial tenure quamdiu se bene gesserint and hints at a Septennial Act.
Lucas again introduces heads of a Septennial Bill on October 20, 1767. Barry Maxwell introduces heads of a judicial tenure bill the same day. In November, the appointment of James Hewitt, 1st Baron Lifford, as Lord Chancellor of Ireland alienates the Undertakers who had hoped for the post. In addition, the British Privy Council adds a wrecking amendment to the judicial tenure bill, which causes the Irish parliament to reject the bill once returned to Dublin. The council also makes three amendments to Lucas’ bill – to the preamble, to extend the limit from seven to eight years, thus an Octennial Bill, and to bring forward the date of the next general election from 1774 to 1768. According to Francis Plowden, the Privy Council insists on the modification to eight years as a wrecking amendment, expecting that the Irish parliament will reject the bill on principle once any amendment has been made to it, and is disappointed when its amended bill is passed. William Edward Hartpole Lecky calls this “without foundation,” stating the actual reasons for eight years are that the Irish Parliament only meets every second year, and to reduce the chance of Irish and British general elections coinciding.
The Octennial Act reinvigorates the Commons, both with newly elected reformers and with MPs made more active by the prospect of imminent re-election. Changes include more assertiveness over supply bills and Poynings’ Law, easing the penal laws, and securing the Constitution of 1782. There are unsuccessful attempts to shorten the maximum duration, in 1773 by Sir William Parsons and in 1777 by Sir Edward Newenham.