In the 1825 to 1867 era, widespread public demonstrations, some of them violent, escalated to demand reform. The ruling Tories were dead set against anything smacking of democracy or popular rule and favoured severe punishment of demonstrators, as exemplified by the Peterloo Massacre in Manchester in 1819. The Tory ranks were cracking, however, especially when Robert Peel (1788–1830) broke away on several critical issues. Nevertheless, the Whig party gets most of the credit. The middle classes, often led by nonconformist Protestants, turned against the Tories and scored the greatest gains. For example, symbolic restrictions on nonconformists called the Test Acts were abolished in 1828. Much more controversial was the repeal of severe discrimination against Roman Catholics after the Irish Catholics organised, and threatened rebellion, forcing major concessions in 1829.
Financial reform, led by William Huskisson and Peel, rationalised the tariff system, and culminated in the great repeal of the tariffs on imported grain in 1846, much to the dismay of grain farmers. The 1846 repeal of the Corn Laws established free trade as the basic principle by which British merchants came to dominate the globe, and brought cheap food to British workers. A depoliticised civil service based on merit replaced patronage policies rewarding jobs for partisan efforts. Efficiency was a high priority in government, with the goal of low taxation. Overall, taxation was about 10%, the lowest in any modern nation.
Foreign policy became moralistic and hostile to the reactionary powers on the continent, teaming up with the United States to block European colonialism in the New World through the Monroe Doctrine of 1823. Slavery was abolished throughout the British Empire. The Royal Navy stepped up efforts to stop international trade in slaves.
Municipal reform was a necessity for the rapidly growing industrial cities still labouring under a hodgepodge of centuries-old laws and traditions. When Peel took over the Home Office, he abolished the espionage and cruel punishments, ended the death penalty for most crimes, and inaugurated the first system of professional police—who in London to this day are still called "Bobbies" in his honour. The Municipal Corporations Act 1835 modernised urban government, which previously had been controlled by closed bodies dominated by Tories. Over 200 old municipal corporations were abolished and replaced with 179 elected borough councils. Elections were to be based on registered voters, city finances had to be audited in a uniform fashion, and city officials were elected by the local taxpayers.
By far the most important of the reforms was the democratisation of Parliament, which began in a small but highly controversial fashion with the Reform Act 1832. The main impact was to drastically reduce the number of very small constituencies, with only a few dozen voters under the control of a local magnate. Industrial cities gained many of the seats but were still significantly underrepresented in Parliament. The 1831–1832 battle over parliamentary reform was, "a year probably unmatched in English history for the sweep and intensity of its excitement." Every few years an incremental enlargement of the electorate was made by Parliament, reaching practically all male voters by the 1880s, and all the women by 1928. Both parties introduced paid professional organisers who supervised the mobilisation of all possible support in each constituency; about 80% of the men voted. The Tories discovered that their conservatism had an appeal to skilled workers, and also to women, hundreds of thousands of whom were organised by the Primrose League. Women's suffrage was not on the agenda. The abolition of the House of Lords, while often discussed, was never necessary because the upper house repeatedly retreated in the face of determined House of Commons action. After defeating the first two versions of the Reform Act 1832, the Whigs got the king to agree to appoint as many new peers as was necessary to change the outcome. He promised to do so, but convinced the Lords it would be much wiser for them to approve the law.
A weak ruler as regent (1811–1820) and king (1820–1830), George IV let his ministers take full charge of government affairs. He was a deeply unpopular playboy. When he tried to get Parliament to pass a law allowing him to divorce his wife Queen Caroline, public opinion strongly supported her.
After four decades of rule by Pittites and Tories the first breakthrough in reform came in the removal by a Tory government of restrictions on the careers of Protestant Nonconformists in the repeal in 1828 of the laws that required Anglican church membership for many academic and government positions. Much more intense was the long battle over the civil rights of Roman Catholics. Catholic emancipation came in 1829, which removed the most substantial restrictions on Roman Catholics in Great Britain and Ireland. The Duke of Wellington, as Tory prime minister, decided that the surging crisis in largely Catholic Ireland necessitated some relief for the Catholics, although he had long opposed the idea. The other main Tory leader was Robert Peel, who suddenly reversed himself on the Catholic issue and was roundly denounced and permanently distrusted by the Ultra Tory faction of die-hards.
Earl Grey, prime minister from 1830 to 1834, and his rejuvenated Whig Party enacted a series of major reforms: the poor law was updated, child labour restricted and, most important, the Reform Act 1832 refashioned the British electoral system. In 1832 parliament abolished slavery in the Empire with the Slavery Abolition Act 1833. The government purchased all the slaves for £20,000,000 (the money went to rich plantation owners who mostly lived in England), and freed the slaves, most of whom were in the Caribbean sugar islands.
The Whigs became champions of parliamentary reform by making the Reform Act 1832 their signature measure. It significantly reduced the numbers of "rotten and pocket boroughs" (where elections were controlled by powerful families), and instead redistributed seats on the basis of population. It also broadened the franchise, adding 217,000 voters to an electorate of 435,000 in England and Wales. The main effect of the act was to weaken the power of the landed gentry, and enlarge the power of the professional and business middle-class, which now for the first time had a significant voice in Parliament. However, at this point the great majority of manual workers, clerks and farmers did not have enough property to qualify to vote. Many of them received the vote in 1867. The aristocracy continued to dominate the Church of England, the most prestigious military and naval posts, and high society, but not business, industry or finance. In terms of national governmental policy, the democratic wishes of the entire people had become decisive.
Most historians emphasise the central importance of the legislation of the 1830s–60s, although there was a dissenting minority of scholars in the 1960s and 1970s who argued against deep meanings of Whiggish progress because each of the reforms was relatively minor in itself. Historian Richard Davis concludes that the scholarship of the 1970s represented "a vindication of the main outlines of the old "Whig interpretation". That is, the Reform Act 1832 was a response to mounting popular pressure. It was "the culmination of a long historical process, and an important turning point in the emergence of a more liberal and broadly based political system... it deserves its old designation of 'Great.'"
David Thompson has stressed the revolutionary nature of the entire package of reforms:
In all these ways—the organization of the new police (by Peel as Home Secretary in the 1820s), the new Poor Law, and in the new municipal councils—the pattern of government in England was changed fundamentally within a single decade. In conjunction with the removal of religious disabilities, these reforms laid the structural foundation for a new kind of State in Britain: a State in which the electoral rights and civil rights of citizens were extended and given greater legal protection, but in which the ordinary citizen was subjected to a much greater degree of administrative interference, direction, and control from the centre. The most spectacular element in this whole process—the Reform Bill of 1832—ensured that the state should also be partially democratized at the centre. The full significance of 1832 in the history of the country is appreciated only if it is seen as the central change in this mini-sided transformation of an agricultural nation ruled by squires, parsons, and the wealthy landowners into an industrial nation dominated by the classes produced by industrial expansion and commercial enterprise.
Chartism was a large-scale popular protest movement that emerged in response to the failure of the Reform Act 1832 to give the vote to the working class. It lacked middle-class support, and it failed repeatedly. Activists denounced the "betrayal" of the working classes and the "sacrificing" of their "interests" by the "misconduct" of the government. In 1838, Chartists issued the People's Charter demanding manhood suffrage, equal-sized election districts, voting by ballots, payment of Members of Parliament (so that poor men could serve), annual parliaments, and abolition of property requirements. The ruling class saw the movement as dangerous. Multiple large peaceful meetings across England demanded change but the Chartists were unable to force serious constitutional debate. In July 1839, however, the House of Commons rejected, by 235 votes to 46, a motion to debate the Chartists' national petition, bearing 1.3 million signatures. Historians see Chartism as both a continuation of the 18th century fight against corruption and as a new stage in demands for democracy in an industrial society.