A member of a Catholic gentry family which had been seated in county Carlow from the seventeenth century, Blackney leased 800 acres of land from Lord Kenmare at Ballyellin.
As a local election organizer, Blackney gave greater priority to the registration of Liberal voters than to the formation of a county club, and, despite attending O’Connell’s National Council in January 1833, does not appear to have been an enthusiastic repealer.
Shortly after his return Blackney made representation to the marquis of Anglesey, the Irish viceroy, regarding the policing of county Carlow. He had long been critical of the tactics of the local yeomanry, and in March 1833 presented petitions against the Irish coercion bill. He also challenged statements made by Lord Duncannon, a former Conservative member and heir to the earl of Bessborough, on the condition of Carlow, denying that it was in a ‘disturbed state’.
Blackney was absent from Hume’s motion on the corn laws, 8 Mar. 1834, but opposed Lord Althorp’s motion for church rates to be replaced by a central grant raised from land tax, 21 Apr. He voted for O’Connell’s repeal motion, 29 Apr., and divided in favour of a select committee inquiry into the pensions list, 5 May. He does not appear to have sat on any select committees or introduced any bills, but chiefly concerned himself with the tithe question, believing ‘in his soul, that no measure’ brought in by the government ‘would ever pacify the people of Ireland’ other than their ‘entire abolition’.
Blackney appears to have been a rumbustious character, his detractors alluding to his ‘blustering manner’.
Blackney’s performance in parliament does not appear to have impressed the Liberator. Prior to the 1835 general election, O’Connell informed Nicholas Aylward Vigors, the repeal member for Carlow Town, that both county members ‘know they will not answer’, and ought to be replaced. Blackney duly retired to make way for Maurice O’Connell, and dutifully proposed him at the general election.
Blackney died suddenly of an apparent heart attack at his residence in September 1842, after visiting friends near Kilkenny.
