The Factory Act of 1847, also known as the Ten Hours Act was a United Kingdom Act of Parliament which restricted the working hours of women and young persons (13-18) in textile mills to 10 hours per day. The practicalities of running a textile mill were such that the Act should have effectively set the same limit on the working hours of adult male mill-workers, but defective drafting meant that a subsequent Factory Act in 1850 imposing tighter restrictions on the hours within which women and young persons could work was needed to bring this about. With this slight qualification, the Act of 1847 was the culmination of a campaign lasting almost fifteen years to bring in a 'Ten Hours Bill'; a great Radical cause of the period . Richard Oastler was a prominent and early advocate; the most famous Parliamentarian involved was Lord Ashley who campaigned long and tirelessly on the issue (although he was not an MP in the session when the Act was passed), but the eventual success owed much to the mobilisation of support among the mill-workers by organisers such as John Doherty and sympathetic mill-owners such as John Fielden, MP who piloted the Act through the Commons. The 1847 Act was passed soon after the fall from power of Sir Robert Peel's Conservative government, but the fiercest opponents of all ten-hour bills were the 'free trade' Liberals such as John Bright; the economic doctrines that led them to object to artificial tariff barriers also led them to object to government restricting the terms on which a man might sell his labour, and to extend that objection to women and young persons.
The Factory Act of 1847 stipulated that as of 1 July 1847, women and children between the ages of 13 and 18 could work only 63 hours per week. The Bill further stipulated that as of 1 May 1848, women and children 13–18 could work only 58 hours per week, the equivalent of 10 hours per day.
The 1833 Factory Act had specified an eight-hour working day for children (aged nine to thirteen) and a twelve-hour day for 'young persons' (fourteen to eighteen) but it had proved difficult to enforce, and its attempts to ensure the education of mill-children had failed. Under the Whig government of Lord Melbourne, Fox Maule had repeatedly produced draft factory bills which were to replace the 1833 Act and better address these issues, but the Whigs had never found the political will and the parliamentary time to get a new Factory Act passed. Maule's later draft bills had proposed reducing the working hours for children to allow better access to better education, but had otherwise left hours of work unchanged. A short-time movement in the textile districts sought a ten-hour day for all millworkers, which it believed would be effectively secured by reducing the working hours for young persons: Lord Ashley supported their cause.