Local Government Secretary Steve Reed has written to all council leaders in England warning them not to introduce four-day working weeks.

As reported by the Telegraph, the letter is understood to say that “council staff undertaking part-time work for full-time pay without compelling justification would be considered an indicator, among a wide range of factors, of potential failure”.

He added that he hoped he had made the government’s policy “unambiguously clear to all councils”.

A Labour source said “Voters deserve high standards and hard work from local councils, and seeing council staff working a four-day week just won’t cut it.”

“They should get on with the job and make sure residents get the best service possible five days a week,” the source added.

In the letter to the councils, which was reported by The Telegraph, Reed says that local authorities should not be offering “full-time pay for part-time work”.

Reed previously expressed his “deep disappointment” in the first UK council to adopt a four-day working week.

South Cambridgeshire District Council, which is led by the Liberal Democrats, became the first to make a permanent move to a four-day week in July after it began trialling a shorter working week in 2023.

Reed said there had been a decline in performance in the council’s housing service and he sked how the local authority would “mitigate” this.

The government can intervene in any council if it is deemed to be failing.

Last year Prime Minister Sir Keir Starmer also rejected civil servants’ demands for a four-day working week.

Critics of a four-day week say it would reduce productivity and slow economic growth but others disagree.

A trial in the Scottish public sector this year found an increase in productivity and improvements in staff well-being.

The Autonomy Institute, which was commissioned by the Scottish government to co-ordinate the pilot, found that 98% of staff judged morale and motivation to have improved.