According to reports, business secretary Lord Mandelson is expected to reveal the findings of the Hooper independent review, which is thought will recommend a move that could see a third of the state-owned firm sold to a private company.

The Daily Telegraph today reported that the deal, which could be valued at around £3bn, would result in part of Royal Mail being sold to a foreign competitor. The Communications Workers Union (CWU) said this would put up to 50,000 jobs at risk.

It is also believed that the government could take over Royal Mail's reported £22bn pension fund – a step that would make a bid for the operator a more attractive proposition for a potential buyer, in light of its pension deficit, which is thought to be in the region of £7-8bn.

Names being mooted as possible buyers so far include TNT and Deutsche Post courier DHL.

Earlier this year, figures in the UK direct mail industry put their weight behind a move to privatise Royal Mail, calling the proposal a positive move for the sector.

Elsewhere, up to 2,000 Royal Mail sorting office workers could take part in a 24-hour strike this Friday (19 December) in protest of proposed mergers of some sites.

Employees in Coventry, Crewe, Liverpool, Stockport, Bolton and Oxford could strike, plunging some Christmas deliveries into disarray.

In a statement from Royal Mail, the operator said the proposed strikes would affect less than 5% of its national workforce.

It added: "We are clearly disappointed that the union would urge strike action at this important and busy time of year and we are asking all our people to get on and deliver the Christmas service our customers want and deserve."

For more on today's announcement, check back later.