Postal workers could take a step closer to industrial action today when Communication Workers Union reps meet in Liverpool.
Delegates are set to debate a motion that calls on regulator Ofcom to "immediately act … to protect the universal service."
The union is worried about the future of the Royal Mail as privateers "cherry pick" profitable work.
The motion calls for private firms to meet the same quality of service and performance standards as Royal Mail.
Postal workers could refuse to handle third-party mail - which makes up almost half of all letters delivered by Royal Mail - in the next few months, the union has warned.
A government guided by common sense would respond to news that publicly owned Royal Mail has increased profits to £403 million by scrapping plans to flog off the service.