This chart shows why the regulation of Royal Mail is under review by Ofcom
The way in which Royal Mail is being regulated in under review by the independent regulator Ofcom - now that it dominates the UK delivery market.
In May, rival delivery business Whistl abandoned plans for door-to-door letter posting and will instead rely on Royal Mail for what it calls "final mile" delivery - getting letters and parcels from local distribution centres to your letter box.
By doing this, Royal Mail now dominates the British delivery scene and the way it is being regulated is under scrutiny - all because its competitor gave up.
"The review will ensure regulation remains appropriate and sufficient to secure the universal postal service, given the recent withdrawal by Whistl from the 'direct delivery' letters market, which has resulted in Royal Mail no longer being subject to national competition. This leaves Royal Mail without any national competition for direct delivery of letters," said Ofcom in a statement on its website.
It gave the following chart to show how Royal Mail now takes up most of the British delivery business after Whistl gave up its services to Royal Mail:
