Houblon’s father-in-law, the Member for Essex, wrote to the prime minister in 1799 to get him excused from the shrievalty that year, pointing out that he had raised a corps of yeomanry at considerable expense.
Faced with another contest in 1812, Houblon refused to share expenses with his colleague Eliab Harvey, who left the field to the Whigs: the political compromise in Essex was thus restored. He continued to vote against Catholic relief, 2 Mar., 24 May 1813, 21 May 1816, 9 May 1817. Government counted on his support and usually got his vote, though he seldom uttered. On 6 June 1815 he appeared in the minority for a committee on the East India ships registry bill. On 6 Mar. 1816 he denied that the county petition against the property tax presented by his Whig colleague conveyed the unanimous sentiment of the country, acquiesced in the relief on agricultural taxation and himself voted for the tax on 18 Mar. On 3 Apr. he was hooted down when attempting to parry the attack on George Rose as treasurer of the navy. His attendance was regular that session. He voted for the suspension of habeas corpus, 23 June 1817. In the ensuing session he failed to muster for the divisions on the ducal marriage grants in April 1818, though he voted with ministers on 21 May. In the Parliament of 1818, too, he was little in evidence, though he presented a petition against Catholic relief, 3 May 1819, was in the majority against Tierney’s censure motion, 18 May, and for the foreign enlistment bill, 10 June.
Houblon retired in 1820. Described by the family historian as ‘amiable and well meaning ... but of a negative personality’, he died 31 May 1831.