As Member for the county from 1783, Smyth supported government, seldom asking a favour,
Shortly before Addington’s ministry fell, Smyth applied to the viceroy for a district paymastership for his bankrupt brother. Hardwicke promised it to him, but finding that Smyth was still in Ireland, 30 Apr. 1804 (the day Addington resigned), ‘desired that it may be intimated in plain terms that the way to get what he wants is to go over to Parliament and support government’. Although Smyth was thought likely to support Pitt’s second ministry, the viceroy had to press for his attendance in May 1805 and hoped he would be induced to undertake the journey by gratitude for ‘attention in two instances concerning which he was anxious’, but Smyth was a widower with an ailing daughter and sought to excuse himself, 1 June. For this he was labelled ‘doubtful’ in July. The Grenville ministry met with the same problem: the chief secretary noted of him: ‘is willing to support government but is not easily got to attend’. Nor did he ever, apparently, utter in debate. Despite this, he promised better support in future and was protected at the election of 1806. He evidently abstained from voting against the Portland ministry on 9 Apr. 1807, but was reported to have done so, with his colleague, on 15 Apr.
There is no evidence that he continued in opposition and when he informed the Castle that he was ready to resign his seat at a convenient moment, 10 Jan. he confidently requested two favours: promotion for his brother, the paymaster of Newry, and the appointment of his friend James Lyne as assistant barrister. On 8 Feb. the chief secretary moved for a new writ although he had not yet been awarded the escheatorship of Munster: the opposition party in Westmeath had been urging Smyth to delay his resignation for their benefit.
