Ministers have formally warned councils in England to abandon any plans to adopt four-day working weeks for staff, in an escalation of a simmering political row over town hall working practices. Government guidance issued on Thursday said councils that have adopted four-day weeks should end the practice immediately, while any authorities planning to embrace it in future should stop any trials immediately. The guidance appears to be the latest salvo in a war of words between the government and South Cambridgeshire district council, which is believed to be the only English authority so far to have experimented with a four-day week. The council has said its continuing trial of the practice, in which office staff and bin collectors are paid the same for working 20% fewer hours, has already helped it improve recruitment and led to over £500,000 in savings on agency workers. Supporters of the four-day week have called it a win-win for workers and employers because it improves staff wellbeing and productivity. In the private sector some companies have adopted the practice after running trials. However, the government believes that a four-day week does not represent value for money and is concerned service quality will slip. The guidance issues veiled warnings that ministers will take unspecified “necessary steps” to ensure the practice is ended. Nationally, council leaders are furious ministers are seeking to restrict councils’ ability to innovate locally. One source called the guidance “a massive overreach” by central government. It is not clear whether there is yet any huge appetite among English local authorities for adopting a four-day week. Norwich city council said last month it would look into the feasibility of trialling a four-day week. The Scottish government is looking at piloting a four-day public sector working week later this year. The minister for local government, Lee Rowley, said: “The government is being crystal clear that it does not support the adoption of the four-day working week within the local government sector. Local authorities that are considering adopting it should not do so. Those who have adopted it already should end those practice immediately.” He added: “Those councils who continue to disregard this guidance are now on notice that the government will take necessary steps in the coming months ahead to ensure that this practice is ended within local government.” The guidance says: “Councils which are undertaking four-day working week activities should cease immediately and others should not seek to pursue in any format. Value for local taxpayers is paramount and no further focus should be given by local authorities on this matter. The department is also exploring other measures to ensure that the sector is clear that this working practice should not be pursued.” Cllr Pete Marland, chair of the Local Government Association’s resources board, said: “More than nine in 10 councils are experiencing staff recruitment and retention difficulties across a diverse range of skills, professions and occupations. “It is councils who know what works best for their community, workforce and in their wider labour market conditions. They should be free to pilot innovative solutions to address local challenges and deliver crucial services to their residents. Local voters should be the ones making a judgment on whether local council leaders have made good choices and delivered value for local taxpayers.”