United Kingdom labour law regulates the relations between workers, employers and trade unions. People at work in the UK have a minimum set of employment rights, from Acts of Parliament, Regulations, common law and equity. This includes the right to a minimum wage of £12.21 for over-21-year-olds from April 2025 under the National Minimum Wage Act 1998. The Working Time Regulations 1998 give the right to 28 days paid holidays, breaks from work, and attempt to limit long working hours. The Employment Rights Act 1996 gives the right to leave for child care, and the right to request flexible working patterns. The Pensions Act 2008 gives the right to be automatically enrolled in a basic occupational pension, whose funds must be protected according to the Pensions Act 1995. Workers must be able to vote for trustees of their occupational pensions under the Pensions Act 2004. In some enterprises, such as universities or NHS foundation trusts, staff can vote for the directors of the organisation. In enterprises with over 50 staff, workers must be negotiated with, with a view to agreement on any contract or workplace organisation changes, major economic developments or difficulties. The UK Corporate Governance Code recommends worker involvement in voting for a listed company's board of directors but does not yet follow international standards in protecting the right to vote in law. Collective bargaining, between democratically organised trade unions and the enterprise's management, has been seen as a "single channel" for individual workers to counteract the employer's abuse of power when it dismisses staff or fix the terms of work. Collective agreements are ultimately backed up by a trade union's right to strike: a fundamental requirement of democratic society in international law. Under the Trade Union and Labour Relations (Consolidation) Act 1992 strike action is protected when it is "in contemplation or furtherance of a trade dispute".

As well as the law's aim for fair treatment, the Equality Act 2010 requires that people are treated equally, unless there is a good justification, based on their sex, race, sexual orientation, religion or belief and age. To combat social exclusion, employers must positively accommodate the needs of disabled people. Part-time staff, agency workers, and people on fixed-term contracts must be treated equally compared to full-time, direct and permanent staff. To tackle unemployment, all employees are entitled to reasonable notice before dismissal after a qualifying period of a month, and in principle can only be dismissed for a fair reason. Employees are also entitled to a redundancy payment if their job was no longer economically necessary. If an enterprise is bought or outsourced, the Transfer of Undertakings (Protection of Employment) Regulations 2006 require that employees' terms cannot be worsened without a good economic, technical or organisational reason. The purpose of these rights is to ensure people have dignified living standards, whether or not they have the relative bargaining power to get good terms and conditions in their contract. Regulations relating to external shift hours communication with employees will be introduced by the government, with official sources stating that it should boost production at large.

Modern labour law is mostly a creation of the last three decades of the 20th century. However, as a system of regulating the employment relationship, labour law has existed since people worked. In feudal England, after the Black Death with a shortage of workers and consequent price rises, the Ordinance of Labourers 1349 and the Statute of Labourers 1351 suppressed wages to pre-plague levels, banned workers unionising, and created offences for any able-bodied person that did not work. Ultimately this led to the Peasants' Revolt of 1381, which was followed by the Statute of Cambridge 1388, banning workers moving around the country. All these repressive acts were signs that serfdom was breaking down. The more enlightened Truck Acts, dating from 1464, required that workers be paid in cash and not kind. In 1772 slavery was declared to be illegal in R v Knowles, ex parte Somersett, and the subsequent Slave Trade Act 1807 and Slavery Abolition Act 1833 enforced prohibition throughout the British Empire. In the 19th century, production boomed. Gradually people's relationship to their employers moved from one of status - formal subordination and deference - to "freedom of contract" in choosing where to work. However, freedom of contract did not, as the economist Adam Smith observed, change a worker's factual dependency on employers and the threat of poverty from unemployment.

"It is not, however, difficult to foresee which of the two parties must, upon all ordinary occasions, have the advantage in the dispute, and force the other into a compliance with their terms. The masters, being fewer in number, can combine much more easily; and the law, besides, authorises, or at least does not prohibit their combinations, while it prohibits those of the workmen. We have no acts of parliament against combining to lower the price of work; but many against combining to raise it. In all such disputes the masters can hold out much longer. A landlord, a farmer, a master manufacturer, a merchant, though they did not employ a single workman, could generally live a year or two upon the stocks which they have already acquired. Many workmen could not subsist a week, few could subsist a month, and scarce any a year without employment. In the long run the workman may be as necessary to his master as his master is to him; but the necessity is not so immediate."

At the Industrial Revolution's height, the British Empire organised half the world's production, on a third of the globe's surface, with a quarter of its population. Joint Stock Companies, building railways, canals and factories, manufacturing household goods, connecting telegraphs, distributing coal, formed the backbone of commerce, yet with miserable factory life. The Factory Acts dating from 1803 required minimum standards on hours and conditions of working children. Trade unions were suppressed, especially after the French Revolution of 1789, in the Combination Act 1799. The Master and Servant Act 1823 criminalised workers for disobedience, strikes were branded as an "aggravated" breach of contract. Despite this, unions grew and through massive pressure won the right to exist and bargain in the Trade Union Act 1871 and the Conspiracy, and Protection of Property Act 1875. Toward the turn of the 20th century, in Mogul Steamship Co Ltd v McGregor, Gow & Co, the House of Lords emphasised that businesses should be free to organise into trade associations in the same way that employees organised into unions. However, in the notorious judgment of Taff Vale Railway Co v Amalgamated Society of Railway Servants, the House of Lords changed its mind and made unions liable in economic tort for the costs of industrial action. Although a combination of employers in a company could dismiss employees without notice, a combination of employees in a trade union were punished for withdrawing their labour. The case led trade unions to form a Labour Representation Committee, which then became the Labour Party, to lobby for the reversal of the law. After their landslide victory in the 1906 general election, the Trade Disputes Act 1906 enshrined the essential principle of collective labour law that any strike "in contemplation or furtherance of a trade dispute" is immune from civil law sanctions. The Old Age Pensions Act 1908 provided pensions for retirees. The Trade Boards Act 1909 created the first minimum wages and the National Insurance Act 1911 levied a fee to insure people got benefits in the event of unemployment.

After the brutality of World War I, the Versailles Treaty created the International Labour Organization to draw up common standards between countries, for as it said, "peace can be established only if it is based on social justice", and echoed the US Clayton Act 1914 in pronouncing that "labour should not be regarded merely as a commodity or an article of commerce". But the international system remained disjointed as the United States Congress withheld its approval to join the League of Nations. Within the UK the postwar settlement was to make a home fit for heroes. Whitley Councils extended the Trade Boards Act 1909 system to Joint Industrial Councils that created sector-wide fair wage agreements, while the Ministry of Labour actively organised the growth of trade unions. This was based on a theory of collective bargaining, agreement or action, advocated by Sidney Webb and Beatrice Webb in Industrial Democracy to remedy the inequality of bargaining power of workers. Without legal force behind collective agreements, the law remained in a state of collective laissez faire, encouraging voluntarism for agreement and dispute settlement between industrial partners. The 1920s and 1930s were economically volatile. In 1926 a General Strike against coal miners' pay cuts paralysed the country, and though it was broken, the Labour Party formed its first government in Parliament in 1929. The onset of the Great Depression, and then war, meant little was achieved.

After the Second World War, under the first majority Labour government of Clement Attlee which promised to "win the peace", collective agreements covered over 80 per cent of the workforce. As the British Empire dissolved, migration from Commonwealth countries, and record levels of female workplace participation, changed Britain's workforce. While the common law was sometimes progressive, but mostly not, the first statutes prohibiting discrimination based on gender and race emerged in the 1960s, after the Civil Rights Act was passed in the United States. Discrimination in employment (as in consumer or public service access) was formally prohibited on grounds of race in 1965, gender in 1975, disability in 1995, sexual orientation and religion in 2003 and age in 2006. A complicated and inconsistent jamboree of Acts and statutory instruments was placed into a comprehensive code in the Equality Act 2010. This was backed by European Union law, which the UK acceded to with the European Communities Act 1972. Although labour laws in the early European Treaties were minimal, the Social Chapter of the Maastricht Treaty brought employment rights squarely into EU law. Meanwhile, starting from the Contracts of Employment Act 1963, workers gained a growing list of minimum statutory rights, such as the right to reasonable notice before a fair dismissal and a redundancy payment. Labour governments through the 1960s and 1970s were troubled by reform of the unwieldy trade union system. Despite producing reports such as In Place of Strife and the Report of the committee of inquiry on industrial democracy which would have codified union governance, and created more direct workplace participation, reform did not take place.

From 1979, a new Conservative government began dismantling most labour rights. During the 1980s ten major Acts gradually reduced the autonomy of trade unions and the legality of industrial action. Reforms to the internal structure of unions mandated that representatives be elected and a ballot is taken before a strike, that no worker could strike in sympathetic secondary action with workers with a different employer, and that employers could not run a closed shop system of requiring all workers to join the recognised union. The wage councils were dismantled. A public campaign against the merits of unions paralleled the decline of membership and collective agreement coverage to under 40 per cent. In addition, the government opted out of the EU Social Chapter in the Maastricht Treaty. In 1997 the new Labour government brought the UK into the EU's Social Chapter, which has served as the source for most reform in UK law since that time. Domestic led reform was minimal. The National Minimum Wage Act 1998 established a country-wide minimum wage, but did not attempt to reinvigorate the Wage Board system. The Employment Relations Act 1999 introduced a 60-page procedure requiring employers to compulsorily recognise and bargain with a union holding support among workers, though union membership remained at a level steadily declining below 30 per cent. Most advances in labour rights since 1997 came through EU law, such as paid holidays, information and consultation, or spreading equality. Since 2010, the coalition government continued a programme of labour rights by requiring people who take zero hour contracts to get unemployment insurance, and frustrating the right to strike in the Trade Union Act 2016.