Tighe sat in the Irish parliament for the boroughs of Banagher (1788-90), Wicklow (1790-7) and Innistioge (1798-1800): of the last two he was proprietor and received £30,000 compensation at the Union. In 1791 it had been reported of him:
It’s uncertain what part young Tighe will take in politics. The Ponsonbys will have him if they can, and his uncle Edward Tighe, who is in office, and a strong government man ... will endeavour to influence him to support; he will be a prize ...
His cousins the Ponsonbys had him, for he went into opposition and actively opposed the Union, which left him without a seat. He did, however, have a significant interest in county Wicklow and nominated George Ponsonby at his election in January 1801. He had offered to stand for the county himself in 1797 if Earl Fitzwilliam supported him, but according to one of his enemies he was so unpopular among the ‘loyal’ gentlemen that not one would speak to him at the spring assizes in 1798. In 1802 he published a Statistical account of Kilkenny and subsequently a long poem, The Plants.
When the Whigs came to power in 1806 and George Ponsonby’s elevation to the lord chancellorship of Ireland opened county Wicklow, Tighe confidently solicited Fitzwilliam’s aid, promising to support the new ministry ‘with many of whom I am full as much connected in political sentiments as by blood’. He was duly returned unopposed, but even in his address, 5 Mar., he had referred to his ‘indifferent state of health’, and his asthma proved a handicap to his parliamentary career. He was urged to attend as soon as elected, but taken ill at Oswestry, 21 June, and obliged to return to Ireland to recoup his strength.
Tighe reached Westminster after his re-election in 1806, but his support for his friends in power was unobtrusive until they fell, when he voted for Brand’s motion on 9 Apr. and sprang to their defence in the debate of 15 Apr. 1807. In his speech he claimed that they were the only ministry so far to have attempted to honour the pledges given at the Union to Ireland.
Tighe was critical in debate of government conduct towards the Irish Catholic convention, 7 Mar. 1811, and on 14 and 27 May pleaded for religious toleration for Catholic militia officers. On 31 May, when he again voted for Catholic claims, he complained that Irish history had been based on a master-servant relationship. He called for the fulfilment of the Union pledges on Irish breweries, 2 Apr., and on Irish tithes, 11 June. He then retreated to Brighton, where Lord Glenbervie characterized him as the ‘strange but very ingenious learned husband’ of ‘the beautiful, cheerful, gentle, amiable Mrs Tighe’. By 4 Feb. 1812 he had left, ‘though still unwell’, to vote for Morpeth’s motion for an inquiry into the state of Ireland. On 24 Feb. he was in the opposition majority against McMahon’s sinecure and on 27 Feb. seconded Sir Thomas Turton’s motion on the state of the nation, in ‘a very long speech’, acting as opposition spokesman but unrehearsed, for as Canning put it there ‘never were such speeches to usher in a delicate question and a difficult vote’.
The last administration was composed out of the relics and dregs of the government of Mr Pitt, which, when voted incapable, wisely relinquished office. Secret influence restored them, and Mr Perceval was placed at their head. After his death the House of Commons again declared them incapable, they again prudently resigned, and again secret influence restored them. What confidence was the country to repose in these relics of relics, these dregs of dregs, this rump of the rump of an administration?
Apart from supporting Irish tithe reform, 23 June, 7 July 1812, he took up the case of an Irish murderer, Walter Hall, said to have been reprieved for his Orange sympathies, and made the debate on the preservation of the public peace bill, 10 July, a pretext for a diatribe against the atrocities alleged to have been committed in suppressing the Irish rebellion of 1798.
Tighe was less active in the Parliament of 1812. He spoke up for the Catholic claims, 11 Feb. 1813, and voted for them, 2 Mar., 13 and 24 May, again speaking on the last date. He was also a spokesman for the Irish brewing interest, 14 May 1813. He appears to have been absent in 1814. He paired against the resumption of war, 25 May 1815, and against the Regent’s expenditure, 31 May, but attended to vote for the Catholics, 30 May, and against the Duke of Cumberland’s grant, 29 June. On 28 Feb. and 8 Mar 1816 he voted and spoke against the army estimates. Tighe died 19 Mar. 1816.