It is not known exactly at what time the borough first exercised the elective franchise, but it returned two members to parliament long prior to 1652, and continued to do so without interruption till the Union, since which time it has returned only one to the Imperial parliament. The right of election, previously vested in the corporation, was, by the act of the 2nd of Wm. IV., cap. 88, extended to the £10 householders and limited to the resident freemen; the total number of registered electors up to June 1st, 1837, was 224, of whom 192 were £10 householders, and 32 freemen; the sovereign is the returning officer. The borough and liberties comprise an area of 11,000 acres, within the jurisdiction of the borough magistrates; a new electoral boundary has been drawn close round the town, including the village of Scilly, and comprising an area of 273 acres.

From the Point on the North-east of the Town at which the new Cork Road crosses the old Cork Road, in a straight Line to the Northern Extremity of Mr. Hurley's Stables; thence in a straight Line to the Point at which the Road to Bandon River leaves the Road to Bandon; thence in a straight Line to the Point at which the Blindgate Road meets the Compass Hill Road; thence in a straight Line over Compass Hill to the Westernmost House at the place called "The World's End;" thence along the Coast to the Point at which the same is met by the first Bank which runs up the Hill to the East of and beyond the Village of Scilly;thence along the said Bank to the Point at which the same meets the Road from Scilly to Charles Fort; thence in a straight Line to a Point on the Harbour Hill Road which is distant One hundred and eighty Yards (measured along the Harbour Hill Road) to the East of the Barrack Wall; thence in a straight Line to the Point first described.