Birch, a Unitarian, had various commercial interests, including East Indian stock and West Indian property, centred on Liverpool, where he had once harboured electoral ambitions and still occasionally participated in political affairs.
He divided against Wilberforce’s compromise motion on the Queen Caroline affair, 22 June 1820, and, as in his vote to censure ministers’ conduct towards her, 6 Feb. 1821, he acted consistently in the opposition campaign on her behalf early the following year. Following his presentation of the Nottingham corporation’s petition for ending the proceedings against her, he urged William Heygate to ‘change his view of the question’, 26 Jan., and he was in the minority on Denman’s motion to print one from the inhabitants for the impeachment of ministers, 20 Feb. He attended the City of London Tavern reform dinner, 10 Feb.
Birch voted for Hume’s amendment to the address on distress, 5 Feb., and against the suspension of habeas corpus in Ireland, 7 Feb. 1822. He was shut out of the division on the 11th, but sided with opposition for another for more extensive tax reductions to relieve distress, 21 Feb., and divided frequently for economies that year. He was in minorities for inquiry into Sir Robert Wilson’s* court martial, 13 Feb., to vote interference with Members’ post a breach of privilege, 25 Feb., and for the remission of the remainder of ‘Orator’ Hunt’s* prison sentence, 22 Mar., 24 Apr. He deprecated rumours that lobbyists for the landed interest were pressing government to assist in raising the price of corn, 25 Mar., urging that reduced taxation was the only equitable means of providing relief ‘not only to the agricultural interest, but to all classes of the community’.
Birch was added to the standing committee of the West India planters and merchants’ committee, 10 Feb. 1824.
Birch stood again for Nottingham at the general election that summer, when he reaffirmed his support for economies and his opposition to the corn laws and pledged to vote for the abolition of slavery. Repudiating opposition attempts to foment a bread riot, he cautioned his supporters against unwittingly assisting in an attempt to unseat him by petition, just ‘as he was before, by perjury’. He was returned at the head of the poll, with his former Whig colleague Lord Rancliffe, after a severe contest against a Tory pretender.
On voting for repeal of the Test Acts, 26 Feb. 1828, he objected to ‘those odious and intolerant laws which had so long disgraced our statute book’. He voted to transfer East Retford’s seats to Birmingham, 21 Mar., and spoke for relaxing the corn laws, 22 Apr., dividing in this sense on 29 Apr. He voted in minorities to rationalize the law relating to customs and excise prosecutions, 1 May, and against the archbishop of Canterbury’s registrar bill, 16 June. He brought up, but declined to endorse, the Nottingham Sion chapel petition against Catholic relief, 8 May, and voted in favour of this, 12 May. He presented the Nottingham artisans’ petition against repealing the Small Notes Act, 20 June, declaring that ‘whatever attempts may be made to restrain the march of intellect, these petitioners are advancing at double quick time’. He paired against the misapplication of public money on Buckingham House, 23 June, and voted against the additional churches bill, 30 June, and to reduce the salary of the lieutenant-general of the ordnance, 4 July 1828. On bringing up two favourable Nottingham petitions, he applauded the ‘wise and honest course’ adopted by the Wellington administration, 18 Feb., and duly voted for Catholic emancipation, 6, 30 Mar. 1829. He was incredulous of the West India Dock Company’s need to raise capital, 14 Apr. He divided to transfer East Retford’s seats to Birmingham, 5 May, against O’Connell’s exclusion from the House for refusing to swear the oath of supremacy, 18 May, and for Lord Blandford’s reform motion, 2 June. On a visit to his constituents in June 1829 he criticized ministers for their political failings, especially in not pressing forward with essential commercial liberalization.
He did not vote for Knatchbull’s amendment to the address, 4 Feb., but insisted on the extent of national distress, 8 Feb. 1830, alluding to the ‘inconceivably distressing’ condition of factory employees in Leeds and Sheffield, as well as the ‘almost entire destitution’ of Nottingham’s work force. He called on government to implement its proposed salutary reforms without delay, though he remained confident of the economy’s viability. He divided for reduced taxation, 15 Feb., and subsequently participated regularly in the opposition’s renewed campaign for economies that session. He voted for parliamentary reform, 18 Feb., to enfranchise Birmingham, Leeds and Manchester, 23 Feb., and again to transfer East Retford’s seats to Birmingham, 5 Mar.; he paired for reform, 28 May. On 17 Mar. he commended a Nottingham petition against the truck system to the House as ‘a sensible and touching description of the hardships to which a most deserving class is exposed by this oppressive practice’; he brought up others against the sale of beer bill, 1 Apr., 4 May, and divided against the measure, 1 July. He voted for Jewish emancipation, 5 Apr., 17 May. He paired for abolition of the death penalty for forgery, 24 May, and divided for this in person, 7 June. He paired for inquiry into the Canadian judiciary, 25 May, but was present to vote for one on the government of Ceylon, 27 May. He attended the meeting of Members interested in the West Indian colonies, 2 June, but voted for Brougham’s motion to end colonial slavery, 13 July 1830.
Despite having reached the age of 75, Birch intended to stand again at the general election that year, but at length declined on grounds of ill health, feeling unequal to the heavy session which lay ahead.
