Robertson told the House of Lords foreign trade committee, 20 June 1820, that he was involved in the China trade and had been to Canton nine times between his first visit in 1795 and his last in 1812. As a ship owner, he emphasized the importance of fully opening that market to private enterprise.
He was a regular attender who gave general support to Lord Liverpool’s ministry, but he opposed them on specific issues and expressed strong views on commercial and financial questions. He was named to the foreign trade committee, 5 June 1820, and in the next four sessions. He divided against economies in revenue collection, 4 July 1820. He voted in defence of ministers’ conduct towards Queen Caroline, 6 Feb. 1821. He divided against Catholic relief, 28 Feb. He was in the minorities for army reductions, 14, 15 Mar., on the Baltic timber duties, 5 Apr., and the composition of the Irish revenue commission, 15 June, and against the grant for the aliens office, 29 June. On the other hand, he voted with government against repeal of the additional malt duty, 3 Apr., for the barracks grant, 28 May, and against Hume’s economy and retrenchment motion, 27 June. He divided against parliamentary reform, 9 May 1821. He voted against more extensive tax reductions, 11, 21 Feb., but was against government on the time limit for conversion of the navy five per cents, 8 Mar., and abolition of one of the joint-postmasterships, 13 Mar. 1822. He opposed repeal of the house and window taxes, 2 July, but thought ‘it was impossible the country could go on under the present [financial] system’ and said he ‘looked with much apprehension to the consequences of some of the measures which had been adopted’. He presented a London merchants’ petition for ‘freer commercial intercourse’ with India, 2 Apr.
On 14 Feb. 1823 Robertson asserted that the ‘one great cause’ of distress was ‘the system of credit’ adopted during the French wars, when vast sums had been borrowed ‘on ruinous terms’. The country was therefore ‘completely in the hands of a great monied body in [the] metropolis’ who could keep interest rates ‘as high ... as they chose’. He stressed the need to support the landed interest, ‘upon which ... the government must principally rely for its resources’, 21 Feb. He traced and deplored successive governments’ departure from the original principle and practice of the sinking fund, 3 Mar., and maintained that ‘the system was an entire delusion, which threatened the ruin of the country and the subversion of the throne, for ... if the aristocracy ... were destroyed the other institutions ... could not stand’. However, he concluded that low interest rates were ‘perhaps the only thing that could enable our merchants and manufacturers to cope with the markets and productions of other countries’, and resolved to support the government’s proposals for regulation of the fund, while urging the importance of securing ‘just’ rates of interest and a fixed amount of capital debt for repayment, in order to ‘do away with stock-jobbing’; he duly voted with ministers later that day. He divided with them against repeal of the assessed taxes, 18 Mar., but spoke and voted against the naval and military pensions bill, 11, 14, 18 Apr. He approved the principle of the warehousing bill, 17 Mar., but complained that it exhibited ‘unnecessary caution’, 21 Mar.
He voted for information on Catholic burials, 6 Feb., and spoke and voted for inquiry into the Irish church establishment, 6 May 1824. Next day, claiming that he ‘belonged to no party’, he complained of misrepresentation of his speech in the Globe, but, harried by the Speaker, he let the matter drop.
He earned cheers when he attacked the Irish unlawful societies bill, 15 Feb. 1825, observing that ‘the Catholic peasantry had been deserted by the landed gentry, Protestant as well as Catholic, and left unprotected against the oppressions of partial magistrates and all the exactions of unfeeling tithe collectors’. He believed that ‘the only advisable measure by which they could put down the violence and discontent which now raged in Ireland would be by concession, not by coercion’; he again voted against the bill, 21 Feb. He divided silently for Catholic relief, 1 Mar., but confessed, 19 Apr., that ‘in a political point of view’ he was less inclined to indulge English and Scottish Catholics. While he voted for the principle of the relief bill, 21 Apr., he tried to insert a clause to prohibit Catholics from representing English and Scottish constituencies, 6 May. He divided for the bill’s third reading, 10 May, but remarked that if it was to be ‘coupled’ with the disfranchisement of Irish 40s. freeholders, ‘it was a question with him how far its supporters ... were bound to advocate it’. He remained hostile to Dissenters’ claims, 25 Mar., 2 May, 21 June, as ‘the Church of England was essential to the safety of the throne’. He again opposed repeal of the usury laws, 17 Feb. He defended the navy estimates against Hume’s strictures, 21 Feb., but saw no valid reason for ‘any augmentation of the army’, 11 Mar., and spoke and voted with the minority for information on the Indian army, 24 Mar. He supported Hume’s unsuccessful attempt to debar Members from voting on questions in which they had a direct pecuniary interest, 10 Mar. He approved the Canadian waste lands bill, 15 Mar. Next day he opposed the Peruvian Mining Company bill, arguing that ‘all the speculations that were at present afloat ... particularly the mining speculations, afforded little chance of being successful’. He spoke and was a minority teller against the third reading of the Equitable Loan Company bill, ‘an undue interference with the pawnbrokers’, 24 Mar.
In a ponderous diatribe during the debate on the address, 2 Feb. 1826, Robertson claimed to have predicted the ‘unavoidable consequences’ of ‘open and barefaced spoliation ... by the machinations of joint-stock companies’, and blamed the current financial crisis on the ‘speculative and gambling system of commerce’ encouraged by ministers. Attributing the country’s problems to the £189,000,000 excess of exports over imports since 1815, he called for protection of domestic industry to ensure that capital was kept at home: he ‘considered the doctrine of absolute free trade, as applied to this country, as the most vicious principle which had ever been adopted by thinking men’. His complaint of press misrepresentation of his speech was cut short by the Speaker, 6 Feb.
The disfranchisement of Grampound came into effect at the dissolution in June 1826 and left Robertson without a seat. His unsuccessful candidature for Durham in February 1828, against the re-election of Sir Henry Hardinge, the secretary at war in the duke of Wellington’s ministry, was nominal and involuntary.
