What is happening to the Royal Mail?

The union representing the UK's postmen and women has agreed a deal to settle the long-running dispute over pay, modernisation and working conditions at Royal Mail.

But why is the Royal Mail in trouble and how has the postal market changed in recent years?

Although there are around 30 other postal services in the UK, the Royal Mail remains by far the largest. It delivers 99% of all the letters in the UK, which in 2009 meant it handled 75 million letters each day.

Graph showing who posts letters in the UK

Graphic showing Royal Mail's domination of the letter delivery market

However, the postal market in the UK is now in decline. The volume of letters delivered by the Royal Mail has fallen from a record high of 84 million a day in 2005.

One of the biggest factors has been the rapid increase of internet access, with 70% of homes in the UK now online.

Graph showing the rise of the internet since 2000

The impact of the internet and other communication technologies, such as mobile phones, has been so great that it has actually severed the link between the postal market and economic growth.

Graph showing how technology has affected postal trends

Previously, fluctuations in the amount of post each year followed the changes in general wealth in the UK. But since 2002, that link has been broken and is unlikely to be restored.

As a result, the Royal Mail finds itself as the biggest fish in a shrinking pool. The Royal Mail letters and packages business has the largest turnover among the businesses that make up Royal Mail Group and employs the most people.

Chart showing how Royal Mail fits into the Royal Mail Group and the number of postmen it employs

There have been large cuts as part of the company's modernisation plans and both Royal Mail Group and the Communication Workers Union agree further savings are needed. But they disagreed over the size of the cuts and how they would affect those who stayed.

The Royal Mail Group also faces a pension deficit estimated to be around £8bn.

The deficit has been a factor in the government's failure to find a partner for its planned part-privatisation of the Royal Mail, and it may now be forced to underwrite the scheme with public funds.