Rochfort saw active service in the Caribbean, the East Indies and America. His two elder brothers were dead by 1812 and his welfare then became the chief object of his father, the importunate Member for county Westmeath, who was beleaguered with financial problems and a large family. Early in 1817 Rochfort senior sought the support of the Irish secretary Robert Peel* for his bid to have Gustavus considered for ‘promotion and safety in the expected reduction of some regiments’. Peel obliged, but was unable to keep Rochfort off the half-pay list a year later. Both he and his father immediately solicited for him employment on full pay ‘to enable me’, as Rochfort pleaded, ‘to support a wife and large young family’. Again Peel, on behalf of the Irish government, was sympathetic, but the military authorities held out scant hope of being able to accommodate Rochfort. His father continued to seek a civil or military appointment for him, but nothing had been done by the time he died early in 1824, leaving Rochfort with only a modest inheritance and his four younger brothers also very poorly provided for.
Rochfort declined to come forward as his father’s replacement at the ensuing by-election, despite the solicitations of ‘numerous friends’, but at the 1826 general election he offered on the ‘high Protestant interest’ with the backing of Lord Longford, who had dropped his pro-Catholic brother. He was returned after a gruelling contest.
We may now be compared to an Orange with the Peel taken off; but the seeds of the fruit still remain, and will strike root downwards, I trust; so that from them, hereafter, may spring a tree that may extend its branches far and wide.
He presented numerous anti-Catholic petitions, 18, 23 Feb., 3 Mar., when he defended his brother-in-law Mervyn Archdall* against a charge of inciting Irish Protestants to physical violence against Catholics, and voted steadily against the relief bill, which he condemned as ‘a subversion of the constitution’, 23 Mar. He was in the minority of 16 for doubling the Irish freeholders’ electoral qualification, 26 Mar. In October 1829 he was listed among the Tory Ultras who were ‘strongly opposed’ to the ministry. He voted against them on economies, 3 May, and repeal of the Irish coal duties, 13 May, but with them on the grant for South American missions, 7 June 1830. He voted against the second reading of the Jewish emancipation bill, 17 May, and paired against abolition of the death penalty for forgery, 7 June. He defended Westmeath grand juries against Daniel O’Connell’s strictures, 21 June 1830.
At the 1830 general election he offered again for Westmeath and was returned after another contest.
Rochfort voted against the second reading of the revised reform bill, 17 Dec. 1831, and the enfranchisement of Tower Hamlets, 28 Feb., and dismissed as unrepresentative a favourable Westmeath petition, 9 Mar. 1832. He divided against the third reading, 22 Mar. He voted against ministers on the Russian-Dutch loan, 26 Jan. 1832. That day he presented and endorsed a petition against the proposed plan of Irish education, which was anathema to Protestants of all denominations, and demanded that goverment adopt a ‘line of policy ... by which the Protestants of Ireland should be protected, and all unjust demands refused’. On 13 Feb. he expressed his ‘infinite satisfaction’ at Grey’s recent declaration in the Lords of the government’s intention of dealing severely with Irish disorder. When presenting a petition from the lord lieutenant and magistrates of Westmeath complaining of its lawless state, 15 Mar., he called for ‘stronger measures’ for the protection of life and property, though he insisted that he ‘meant to cast no reflection upon the government’. On 20 Mar. he warned that Ireland was in a ‘most alarming’ condition and that ‘the mob have, for some reason or another, taken it into their heads that ... government are disposed to favour their proceedings’. His last recorded votes were for the Liverpool disfranchisement bill, 23 May, and against the second reading of the Irish reform bill, 25 May. He was a founder member of the Conservative Society of Dublin established next month, and contested Westmeath as a Conservative at the 1832 general election, but was beaten into third place by two reformers.
Soon after Peel became premier at the end of 1834 Rochfort wrote to him:
From the kindly manner I have been always treated with by you, I am encouraged to hope for a kind attention to this letter. Indeed I once had a note from you which I shall ever prize, in it you were pleased to express the word esteem (which I have done nothing to forfeit) ... My claims have been acknowledged by the late ministry of the duke of Wellington. You well know my family represented Westmeath for 150 years, always supporting the true interests of the country, my father for 30 years, during which he gave his steady support to the several ministries on those principles which, thanks be to God, have rallied under you for the salvation of the Empire. My father’s private affairs suffered from his constant attendance. His claims were repeatedly acknowledged but the intentions of the ministers were never accomplished. I myself zealously supported the same line. I don’t think I missed a question on the reform bill, and but for the alteration in the ... bill of 1829, instead of six years I should now be the ninth year fighting under your banner. That registry deluged Ireland with false votes. I may add as a soldier I have received the approbation of my superiors.
What he wanted was civil employment for his 19-year-old only son and namesake, but Peel, overwhelmed with similar applications, could give him no hope. (He purchased a cornetcy for his son in the 4th Dragoon Guards in 1836 and a lieutenancy two years later.) Within a month of Peel’s resumption of power in 1841 he solicited a civil or military appointment for himself, but was again disappointed.