The son of a leading northern coal owner and court favourite, Liddell was heir to extensive estates in Northumberland and Durham, and the baronetcy conferred in 1642 on the royalist Thomas Liddell for his defence of Newcastle-upon-Tyne against the Scots. An excellent scholar and classicist, he was intended for a political or diplomatic career and left Cambridge without taking his degree. Overtures to the premier Lord Liverpool by his father, who represented county Durham as a Grenvillite, 1806-7, seeking treasury assistance for Liddell’s candidature in 1818 for Northumberland and in 1820 for county Durham, brought too little reassurance on which to proceed, and, lacking funds to fight independently, he had to bide his time.
Liddell returned to London and Canning’s private office in November 1826.
Speaking on the recent ministerial changes, 4 Feb. 1828, Liddell expressed qualified and conditional support for the duke of Wellington’s administration, asserted that Canning ‘alone was the main strength and stay’ of the late ministry he had adhered to and that ‘its dissolution ... was as much a relief to its friends as ... a measure of satisfaction to its opponents’.
The 3rd duke of Northumberland’s ‘supposed conversion’ to the Catholic cause prompted empty speculation that Liddell would join the Wellington administration directly emancipation was conceded.
Liddell reaffirmed his opposition to reform before voting to transfer East Retford’s seats to Birmingham, 5 Mar. 1830, which concessions, he maintained, afforded the ‘best argument’ against the ‘sweeping reformers’. He said he would also have voted to enfranchise Birmingham, Leeds and Manchester (23 Feb.) had he been in London. Representing the northern coal owners, he called for inquiry into the London coal trade and was named to the committee, 11 Mar., backed the parliamentary campaign for repeal of the coastwise coal duties, 17 Mar., and brought up petitions for it, 3 May. An opponent, to his cost, of the Newcastle-Carlisle railway, he spoke, 3, 4 June, and voted, 3 June, for the Northern roads bill, which the Lowthers bitterly opposed and was now held over.
Liddell reluctantly accepted that some reform was necessary and, projecting himself as a candidate in waiting, he delivered what the 1831-2 boundary commissioner William Henry Ord† termed a ‘sort of half speech which suited neither one side nor the other, being ... like his [parliamentary] speeches intended to suit both’ at the Newcastle meeting of 23 Dec. 1830. Speaking similarly, he again failed miserably at the Durham county meeting, 1 Feb., and in Northumberland, 9 Feb. 1831. He declared against wholesale disfranchisement, but was for transferring single Members from small, depopulated places to manufacturing towns and an extended franchise. He was unexpectedly absent from the Northumberland meeting of 16 Mar.
