Employees at the Department for Environment, Food, and Rural Affairs want to be the first in Whitehall to experiment with the contentious change in working habits.
Ministers ordered councils last month to halt four-day workweek trials and to prohibit any fresh such “experiments.”
The TaxPayers’ Alliance also warned that implementing a four-day workweek across the public sector would cost £30 billion in missed working hours each year.
However, Defra employees propose a pilot plan involving 21,000 employees to determine if lowering working hours by 20% enhances their well-being and productivity.
On Thursday, Defra civil servants from the Public and Commercial Services trade union submitted a petition to their superiors.
They called on them to agree a trial, saying the four-day week is becoming increasingly popular in workplaces across Britain.
General secretary Mark Serwotka said: ‘Evidence suggests a four-day week would lead to a better work-life balance for staff and could improve productivity for the employer.
‘Previous trials have led to a reduction in sick leave and improvements to staff retention and satisfaction.
‘If Defra wants to seriously address the issues of employee burnout, stress and poor well-being, they will listen to our members and implement this pilot.’
The demand, however, is expected to be rejected by the Environment Secretary.
According to a source close to Steve Barclay, ‘this is a wholly unreasonable fringe demand being pushed by hard-left union leaders that is entirely at odds with the hard work and dedication to delivering for the public that our civil servants exhibit every day.’
It comes as ministers continue to encourage the first town hall to implement a four-day week to finish its trial.