On his father’s death in 1824 Lemon inherited all his Cornish property, including interests in several copper mines, and was the residuary legatee of the personal estate, which was sworn under £70,000.
He divided for the second reading of the reintroduced reform bill, 6 July 1831, and generally for its details. However, he voted against Downton’s inclusion in schedule A, 21 July, and for the Chandos amendment to enfranchise £50 tenants-at-will, 18 Aug. He contradicted Wetherell’s assertion that the population of Appleby was equal to that of Truro, 19 July, and commended the ‘most desirable’ union of Penryn with Falmouth, which were ‘both ports increasing in importance’, 9 Aug. He divided for the bill’s passage, 21 Sept., the second reading of the Scottish bill, 23 Sept., and Lord Ebrington’s confidence motion, 10 Oct. Following the Lords’ rejection of the reform bill he attended a county meeting, 26 Oct., when he expressed confidence that the people would avoid ‘violent passions’ as it was ‘a question of time only’ before the measure was carried. He maintained that it would ‘remedy’ the antagonism between the manufacturing and agricultural interests, while ensuring that the latter retained its ‘due weight in the representation’. On the other hand, he was grateful that he had not been asked to pledge support to all its details, as he ‘should have felt great embarrassment in some votes which I have given, departing from the original bill and I think introducing great improvements into it’.
At the general election of 1832 Lemon was returned unopposed for West Cornwall, after pledging support for agricultural protection and the commutation of tithes, and he sat as an advocate of ‘Whig principles’, with one brief interruption, until his retirement in 1857.
