Union appears to accept Royal Mail proposal to cut most Saturday deliveries

CWU seems to concede six-day service is financially unviable as company battles takeover bid

Letterboxes could fall silent on Saturday mornings, after the postal workers' union appeared to accept a proposal from Royal Mail that would abandon its duty to deliver all letters six days a week.

Royal Mail is required to deliver post from Monday to Saturday under the terms of the universal service obligation (USO) set down by an act of parliament in 2011. Amid a long-running industrial dispute with the financially struggling company, the Communication Workers Union (CWU) has so far opposed a 300m cost-cutting blueprint that would include scrapping most Saturday services.