The Three-Day Week was one of several measures introduced in the United Kingdom by the Conservative Government 1970-1974 to conserve electricity, the production of which was severely limited due to industrial action by coal miners. The effect was that from 1 January until 7 March 1974 commercial users of electricity would be limited to three specified consecutive days' consumption each week and prohibited from working longer hours on those days. Services deemed essential (e.g. restaurants, food shops and newspapers) were exempt. Television companies were required to cease broadcasting at 10.30pm during the crisis to conserve electricity.
Throughout the early 1970s, particularly in 1972 and 1973, the British economy was troubled by high rates of inflation. One of the government's strategies to tackle this was to cap pay rises. This caused unrest amongst trade unions in that wages were struggling to keep pace with prices. This extended to most industries, most notably an industry where there was a powerful union – coal mining.
By the middle of 1973, the National Union of Mineworkers had encouraged their members to work to rule - as a result, coal stocks slowly dwindled. The global effect of the 1973 oil crisis also drove up the price of coal. The Heath government entered into negotiations with the NUM, to no avail. To reduce electricity consumption, and thus conserve coal stocks, a series of measures were announced on 13 December 1973 by Heath, including the "Three-Day Work Order", more commonly known as the Three-Day Week, which was to come into force at midnight on 31 December. Commercial consumption of electricity would be limited to three consecutive days each week. Heath's objective was business continuity and survival. Rather than risk a total shutdown, working time was reduced with the intent of prolonging the life of available fuel stocks.
In the February 1974 general election the Conservative campaign emphasised the dispute with the miners and used the slogan "Who governs Britain?". The election resulted in the Conservatives losing seats and Labour becoming the largest party in the Commons, but without an overall majority. Heath failed to secure sufficient parliamentary support from the Liberal and Ulster Unionist MPs, and Harold Wilson returned to power for his third term.
The normal working week was restored on 8 March, but other restrictions on the use of electricity remained in force. A second general election was held in October 1974. This gave Labour an overall majority that was too small to survive the loss of seats in by-elections and eventually led to a Lib-Lab pact.
- Winter of discontent - the period of industrial action and economic problems in the UK in 1978 - 79