Employers testing four-day work weeks with no cut in pay are reporting surging productivity and are likely to make the scheme permanent, backing a Senate inquiry proposal for the federal government to fund a nationwide trial.

Momentum Mental Health chief executive Debbie Bailey told The Australian Financial Review the Queensland charity had extended its six-month trial, which ended on January 1, to a full year after it resulted in an 11 per cent rise in capacity and a 20 per cent increase in client service hours.