Labour is likely to be pressed to renationalise the Royal Mail if it wins the next general election after unions overwhelmingly voted to debate the Government's decision to privatise the service.
The Communication Workers Union (CWU), which is to ballot its members for strikes over issues linked to privatisation, believes it is "vital" Labour is seen to defend a public postal service.
Its motion at the party's conference in Brighton calls for an incoming Labour government to renationalise Royal Mail "in the event of the coalition government actually selling the company".
The future of the Royal Mail is a hot issue
On Sunday, the privatisation of Royal Mail was one of six topics selected by the unions and constituency Labour parties for debate over the next three days.
The exact wording of the motion has yet to be decided. A final motion will be decided shortly so the debates can take place.
The motion reads: "Conference notes the August publication of Royal Mail's executives' pay levels, with its chief executive earning £1.47m."
There are other motions on Royal Mail to be taken in to account but the CWU is urging delegates to oppose privatisation "because it will lead to higher prices for small businesses and domestic consumers, pressure to end the six-day delivery and uniform tariff, a deterioration of services in rural and 'non-profitable' areas, and the prioritisation of shareholder dividends over service provision".
Ballot papers will go out to CWU members on September 27, with the result announced on October 16.
If there is a yes vote, the earliest that strike action could take place would be October 23.
It is the first national strike ballot in Royal Mail since 2009 and will affect 115,000 postal workers in Royal Mail and Parcelforce, but not the Post Office, which is a separate company.
The dispute is over pay, pensions and the impact of privatisation on job security, terms and conditions.
There were five other topics selected for debate today. They were the cost of living, employment rights, lobbying, housing and the NHS.