Chamberlayne was well provided for by his father, who had successively held the posts of solicitor to the mint and treasury and commissioner of the public accounts. He sold his father’s residence at Coley Park, Berkshire, in 1802 and appears to have done the same with the parts of his landed inheritance which lay in Kent and Hertfordshire.
Chamberlayne had first entered Parliament under the aegis of the Pittite George Rose†, but apparently came under the influence of Cobbett and signalled the leftward drift of his politics by raising a monument to Fox at Weston in 1810.
Chamberlayne’s most prominent act of munificence was his gift of iron lamp posts for Southampton, which was lit by gas in 1821. His generosity was commemorated the following year by the erection of ‘Chamberlayne’s column’, an iron obelisk of some 50 feet which, after its removal to the quay in 1829, served as a landmark for shipping. As a local historian has noted, the laudatory inscription on its base omitted to mention that he was chairman of the local gas company when he made his gesture.
Chamberlayne’s age and infirmity had given rise to press speculation that he would retire at the next dissolution, but at the 1826 general election he offered again, giving notice that his physical condition might preclude a full canvass. On the hustings he advocated a remission of taxation, but resolutely refused to be pledged on Catholic relief, on which he had cast no previous recorded vote. He was returned unopposed.
