In spite of his distinction as ‘The MacMorrough’, a lineal descendant of the ancient kings of Leinster, Kavanagh’s status as one of the wealthiest commoners in Ireland was not sufficient to enable him to recapture a seat for County Carlow at the 1832 general election. He came fourth in the poll just behind his son-in-law and fellow Conservative, Colonel Henry Bruen, and their subsequent petition against the result, citing ‘priestly interference’ in the contest, came to nothing.
Kavanagh’s ‘princely’ descent and military experience on the continent furnished him with a reputation as ‘a polished and highly informed gentleman’.
Kavanagh had been known as a lax attender in previous parliaments, and does not appear to have sat on any select committees or introduced any bills.
In spite of having been in ‘excellent health’, the ‘irreparable loss’ of his eldest son and political heir in August 1836 precipitated Kavanagh’s rapid decline. He was absent from a political dinner given in his honour in January 1837, and died at his residence shortly afterwards ‘from the fatal effects of gout in the stomach’.
Kavanagh was succeeded by Thomas, the eldest son by his second marriage, then a minor. Thomas died unmarried from tuberculosis on passage from Sumatra to Australia in 1852, and his brother Charles died the following year after his dressing-gown caught fire shortly before he was due to marry.
