In 1781 Barclay’s father became joint owner of Thrale’s brewery in Southwark, the purchase of which, according to Samuel Johnson, conferred ‘the potentiality of becoming rich beyond the dreams of avarice’.
Penryn was to prove a troublesome berth for Barclay. A petition alleging bribery and corruption was lodged against the return of his colleague William Manning, a fellow director of the Bank who also shared an interest in the Australian Agricultural Company. As the borough had already come under parliamentary scrutiny on two occasions for similar malpractice, a bill of disfranchisement was brought forward with the blessing of Canning’s ministry. Barclay opposed it in his maiden speech, 8 May 1827, when he absolutely denied any wrongdoing on his own part and protested the innocence of most of the electors. On 18 May he expressed his conviction that the borough had ‘been undergoing a gradual change for the better’ since the first parliamentary inquiry in 1807, a point he endeavoured to illustrate in a question to a witness before the committee. He divided against Lord John Russell’s amendment to transfer Penryn’s seats to Manchester, 28 May, after complaining that enthusiasm for this proposal had led to the conviction of the borough on ‘hearsay evidence’, when there existed ‘a hundred others infinitely more corrupt’. The Whig Lord Milton acknowledged that Penryn had been ‘well defended by its present Member’. Barclay again described its exceptional treatment as rank hypocrisy, 7 June 1827, when he was a minority teller against the third reading of the disfranchisement bill. On its revival next session, he claimed that the original petition had been no more than a device to extort money from Manning and observed that the transfer of Grampound’s seats to Yorkshire had simply subjected two more to aristocratic control, 14 Mar. 1828. Yet he had supported the disfranchisement of East Retford in the belief that ‘the evidence was sufficient, if uncontradicted, to justify the measure’, 11 June 1827. He divided against extending its franchise to Bassetlaw freeholders, 21 Mar., the disqualification of named voters, 24 June, and the recommittal of the disfranchisement bill, 27 June 1828. Instead, he voted for the transfer of its seats to Birmingham, 5 May 1829, 11 Feb. 1830.
Barclay’s general politics are difficult to categorize. Unlike his brother, he divided for Catholic relief, 6 Mar. 1827. He voted for repeal of the Test Acts, 26 Feb., and paired for Catholic relief, 12 May 1828. He spoke in favour of an overhaul of London policing, 28 Feb., suggesting that reference should be made to a select committee report of 1817. He quoted with evident distaste the opinion of one law officer in favour of public executions as a deterrent to criminals, and for his own part favoured the wider use of informants. He divided against the duke of Wellington’s ministry for a 60s. rather than 64s. pivot price to regulate corn imports, 22 Apr. He presented a Penryn anti-slavery petition, 30 May 1828. In February 1829 Planta, the patronage secretary, predicted that he would side ‘with government’ for Catholic emancipation, and he voted accordingly, 6, 30 May. He suggested that the signatories to a hostile petition from Penryn were prey to groundless fears about the recovery of monastic land, 24 Mar. 1829. He divided against Lord Blandford’s parliamentary reform plan, 18 Feb., and the enfranchisement of Birmingham, Leeds and Manchester, 23 Feb. 1830. He voted in the minority for Harvey’s motion to prevent Members from voting on bills in which they had a personal stake, 26 Feb. He divided against ministers to omit the Bathurst and Dundas pensions from the civil list, 26 Mar., but with them on the grant to South American missions, 7 June. He voted for Jewish emancipation, 5 Apr., 17 May, and abolition of the death penalty for forgery, 24 May, 7 June. He was in the minority to prohibit consumption on the premises in beer shops, 21 June 1830. He retired at the dissolution that summer.
Following his father’s death in October 1830 Barclay received a one-eighth share in the family brewery, a legacy of £15,000 and a share in the residue of the personal estate, which was sworn under £160,000.
